Last updated on 2020-08-07 01:49:57 CEST.
| Flavor | Version | Tinstall | Tcheck | Ttotal | Status | Flags | 
|---|---|---|---|---|---|---|
| r-devel-linux-x86_64-debian-clang | 0.2.1 | 5.18 | 332.58 | 337.76 | OK | |
| r-devel-linux-x86_64-debian-gcc | 0.2.1 | 4.10 | 260.97 | 265.07 | OK | |
| r-devel-linux-x86_64-fedora-clang | 0.2.1 | 444.59 | OK | |||
| r-devel-linux-x86_64-fedora-gcc | 0.2.1 | 458.97 | OK | |||
| r-devel-windows-ix86+x86_64 | 0.2.1 | 25.00 | 300.00 | 325.00 | OK | |
| r-patched-linux-x86_64 | 0.2.1 | 4.27 | 342.67 | 346.94 | OK | |
| r-patched-solaris-x86 | 0.2.1 | 824.10 | ERROR | |||
| r-release-linux-x86_64 | 0.2.1 | 3.11 | 342.12 | 345.23 | OK | |
| r-release-macos-x86_64 | 0.2.1 | OK | ||||
| r-release-windows-ix86+x86_64 | 0.2.1 | 26.00 | 308.00 | 334.00 | OK | |
| r-oldrel-macos-x86_64 | 0.2.1 | OK | ||||
| r-oldrel-windows-ix86+x86_64 | 0.2.1 | 16.00 | 250.00 | 266.00 | OK | 
Version: 0.2.1
Check: tests
Result: ERROR
      Running ‘testthat.R’ [696s/235s]
    Running the tests in ‘tests/testthat.R’ failed.
    Complete output:
      > library(testthat)
      > library(rBiasCorrection)
      > 
      > test_check("rBiasCorrection")
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      ── 1. Failure: test normal function of file import of type 1 (@test-clean_dt.R#1
      Value hashes to a97f4cf13a, not ab5287b084
      
      ── 2. Failure: test normal function of file import of type 1 (@test-clean_dt.R#2
      Value hashes to a97f4cf13a, not ab5287b084
      
      ── 3. Failure: test normal function of file import of type 1 (@test-clean_dt.R#2
      Value hashes to eccd89265e, not 1fb62d8498
      
      ── 4. Failure: test normal function of file import of type 2 (@test-clean_dt.R#3
      Value hashes to a0ee41e7db, not f8d57b6e9c
      
      ── 5. Failure: test normal function of file import of type 2 (@test-clean_dt.R#4
      Value hashes to a0ee41e7db, not f8d57b6e9c
      
      ── 6. Failure: test normal function of file import of type 2 (@test-clean_dt.R#4
      Value hashes to 875c4d0842, not 516b7aee57
      
      ── 7. Failure: test normal function of file import of type 2 (@test-clean_dt.R#5
      Value hashes to f66b7686fd, not d32a53505b
      
      ── 8. Failure: test functioning of aggregated function (@test-create_aggregated.
      Value hashes to 4a4ed97b38, not 5a885b7e0a
      
      ── 9. Failure: test functioning of aggregated function (@test-create_aggregated.
      Value hashes to 46d527e146, not d042a19f13
      
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        number of iterations exceeded maximum of 50
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        step factor 0.000488281 reduced below 'minFactor' of 0.000976562
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      Error in (function (formula, data = parent.frame(), start, control = nls.control(),  : 
        singular gradient
      ══ testthat results  ═══════════════════════════════════════════════════════════
      [ OK: 181 | SKIPPED: 2 | WARNINGS: 12 | FAILED: 9 ]
      1. Failure: test normal function of file import of type 1 (@test-clean_dt.R#17) 
      2. Failure: test normal function of file import of type 1 (@test-clean_dt.R#21) 
      3. Failure: test normal function of file import of type 1 (@test-clean_dt.R#25) 
      4. Failure: test normal function of file import of type 2 (@test-clean_dt.R#39) 
      5. Failure: test normal function of file import of type 2 (@test-clean_dt.R#43) 
      6. Failure: test normal function of file import of type 2 (@test-clean_dt.R#47) 
      7. Failure: test normal function of file import of type 2 (@test-clean_dt.R#52) 
      8. Failure: test functioning of aggregated function (@test-create_aggregated.R#25) 
      9. Failure: test functioning of aggregated function (@test-create_aggregated.R#30) 
      
      Error: testthat unit tests failed
      Execution halted
Flavor: r-patched-solaris-x86