More functions & fixes in Rphylip

My latest updates to Rphylip, an R interface for Felsenstein's phylogeny methods package PHYLIP, includes Rdnainvar, an interface for dnainvar, a program for Lake's invariants from DNA sequences; and Rfitch, an interface for fitch, a program that does least-squares and minimum evolution phylogeny inference.

In addition to this, though, today I added the functions setPath & clearPath. The former can be used to set the path to the PHYLIP executables folder for the current R session. Normally, Rphylip tries to find the path to the PHYLIP executable using the internal Rphylip function, findPath. However this function only works if the PHYLIP folder is in a sensible location, such as in C:/Program Files/ (for Windows) or /Applications/ (for Mac OS). If not, the path can always be supplied to the function directly. What setPath does is enable the user to set a different place to look for PHYLIP executables for the current R session. It does this by setting the environmental variable "phylip.path". clearPath does the opposite. It removes the environmental variable "phylip.path" thus permitting Rphylip functions to search for PHYLIP executables in the regular places.

Here's a demo in which I have PHYLIP installed in C:/Users/Liam/Documents/Phylogeny_Programs/:

> require(Rphylip)
Loading required package: Rphylip
Loading required package: ape
> packageVersion("Rphylip")
[1] ‘0.1.13’
> data(primates)
> D<-Rdnadist(primates)
Error in Rdnadist(primates) :
  No path provided and was not able to find path to dnadist
> setPath("C:/Users/Liam/Documents/Phylogeny_Programs/phylip-3.695/exe/")
> D<-Rdnadist(primates)

...

Nucleic acid sequence Distance Matrix program, version 3.695

...

> tree<-Rfitch(D)

...

Fitch-Margoliash method version 3.695

...

  12 Populations

Fitch-Margoliash method version 3.695

                  __ __             2
                  \  \   (Obs - Exp)
Sum of squares =  /_ /_  ------------
                                2
                   i  j      Obs

Negative branch lengths not allowed

global optimization


                                         +-----------7
                                +--------2
                                !        !   +-------6
                                !        +---1
                                !            !  +-4
                       +--------3            +--8
                       !        !               +----5
                       !        !
                       !        !      +-----------------8
                       !        +------9
                       !               !   +-------------9
  +--------------------7               +---5
  !                    !                   !    +-------10
  !                    !                   +----6
  !                    !                        ! +------12
  !                    !                        +-4
  !                    !                          +-------11
  !                    !
  !                    +----------------------------3        
  ! 
 10--------------------------------------2
  ! 
  +-------------------------------------1


remember: this is an unrooted tree!

Sum of squares =     0.68048

Average percent standard deviation =     7.23497

...

Translation table
-----------------
        1       Lemur
        2       Tarsier
        3       Sq.Monkey
        4       J.Macaque
        5       R.Macaque
        6       E.Macaque
        7       B.Macaque
        8       Gibbon
        9       Orangutan
        10      Gorilla
        11      Chimp
        12      Human

> plot(tree)