In plant physiology, conductance to heat, carbon dioxide, and water vapour are expressed in different units for different purposes. For heat exchange, units of m/s are most often used, whereas for gas exchange units of either mol/m^2/s (the default output from LICOR devices) or umol/m^2/s/Pa are used. I found it difficult to keep all the conversions straight, so I made a small package to help ensure proper conversion.
You can install the current version of gunit from GitHub with:
Or the released version of gunit from CRAN with:
This is a basic example which shows you how to solve convert conductance units:
library(gunit)
library(units)
#> udunits system database from /Library/Frameworks/R.framework/Versions/3.6/Resources/library/units/share/udunits
g_sw <- set_units(0.4, mol/m^2/s)
convert_conductance(g_sw)
#> # A tibble: 1 x 3
#> `m/s` `umol/m^2/s/Pa` `mol/m^2/s`
#> [m/s] [umol/m^2/Pa/s] [mol/m^2/s]
#> 1 0.009786197 3.947709 0.4
# Change Temperature and Pressure
g_sw <- set_units(0.4, mol/m^2/s)
convert_conductance(g_sw,
P = set_units(80, kPa),
Temp = set_units(293, K))
#> # A tibble: 1 x 3
#> `m/s` `umol/m^2/s/Pa` `mol/m^2/s`
#> [m/s] [umol/m^2/Pa/s] [mol/m^2/s]
#> 1 0.01218068 5 0.4
# Calculations can also be vectorized
g_sw <- set_units(seq(0.1, 0.4, 0.1), mol/m^2/s)
convert_conductance(g_sw)
#> # A tibble: 4 x 3
#> `m/s` `umol/m^2/s/Pa` `mol/m^2/s`
#> [m/s] [umol/m^2/Pa/s] [mol/m^2/s]
#> 1 0.002446549 0.9869272 0.1
#> 2 0.004893099 1.9738543 0.2
#> 3 0.007339648 2.9607815 0.3
#> 4 0.009786197 3.9477087 0.4I welcome comments, criticisms, and especially contributions! GitHub issues are the preferred way to report bugs, ask questions, or request new features. You can submit issues here:
https://github.com/cdmuir/gunit/issues
gunit in R doing citation(package = 'gunit')