Updates to tip label printing and summary method for "cophylo" objects

I just pushed a couple of small updates to the object class "cophylo" plotting method - in particular pertaining to the spacing of tip labels and what to do with underscores in species label names.

First, I recently discovered that (accidentally) by using sub instead of gsub, I was substituting only the first underscore character "_" for a space character " " in species names, instead of all such characters.

This was very easy to fix as gsub works the same way as sub, except that it substitutes all instances of a character pattern as desired, instead of just the first encountered.

Next, however, I realized that the width in a plotting device of "_" and " " differ by more than a factor of two (although this may vary between device types). E.g.:

plot.window(xlim=c(0,1),ylim=c(0,1))
plot.new()

strwidth("_")

## [1] 0.02792554

strwidth(" ")

## [1] 0.01196809

but in computing where to draw the links to tip labels, I had been using strwidth(tree$tip.label) rather than strwidth(gsub("_"," ",tree$tip.label)).

Finally, I have made some changes to the S3 summary method for the object class "cophylo" so that the association matrix prints more nicely! In particular, I tried to space the columns by the longest name in the matrix, rather than just by using tabs.

So, for instance, here is the old methods:

library(phytools)
t1<-read.tree(text="(A_B_C,(C_D_E_F_G_H_I_J_K_L,D_E_F));")
t2<-read.tree(text="(C_D_E_F_G_H_I_J_K_L,(A_B_C,D_E_F));")
obj<-cophylo(t1,t2)

## Rotating nodes to optimize matching...
## Done.

summary(obj)

## 
## Co-phylogenetic ("cophylo") object: obj 
## 
## Tree 1 (left tree) is an object of class "phylo" containing 3 species.
## 
## Tree 2 (right tree) is an object of class "phylo" containing 3 species.
## 
## Association (assoc) table as follows:
## 
##  left:   ----    right:
##   A_B_C  ----     A_B_C 
##   C_D_E_F_G_H_I_J_K_L    ----     C_D_E_F_G_H_I_J_K_L 
##   D_E_F  ----     D_E_F

plot(obj,link.type="curved")

This problem of spacing is particularly apparent, I think, if we shrink the font size:

plot(obj,link.type="curved",fsize=0.6)

Now, let's load the updated source code from GitHub:

source("https://raw.githubusercontent.com/liamrevell/phytools/59f2e02a83f9142d480ad49f7e226ca0d28aeeb6/R/cophylo.R")
summary(obj)

## 
## Co-phylogenetic ("cophylo") object: obj 
## 
## Tree 1 (left tree) is an object of class "phylo" containing 3 species.
## 
## Tree 2 (right tree) is an object of class "phylo" containing 3 species.
## 
## Association (assoc) table as follows:
## 
##  left:               ----    right:
##  A_B_C               ----    A_B_C
##  C_D_E_F_G_H_I_J_K_L ----    C_D_E_F_G_H_I_J_K_L
##  D_E_F               ----    D_E_F

plot(obj,link.type="curved")

plot(obj,link.type="curved",fsize=0.6)

Much better. phytools can also be updated to its latest version from GitHub using devtools.