Quartet is an R package that calculates the Quartet distance between two trees: a measure of their similarity based on the number of shared four-taxon subtrees.
The package uses the tqDist algorithm. Unlike many other implementations, it distinguishes between quartets that are contradicted by one tree, and quartets that are simply absent due to a lack of resolution (i.e. the presence of polytomies). Quartet makes this distinction in both the quartet metric (function QuartetStatus) and the partition metric (i.e. Robinson-Foulds distance; function SplitStatus).
Install and load the library from CRAN as follows:
install.packages('Quartet')
library('Quartet')If you’re feeling brave, you can install the development version thus:
You will need Rtools installed in order to build the development version from source.
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