Trick to name the edges of a "phylo" object (for reference)

In my response to a recent R-sig-phylo message, I posted a trick for assigning the "names" attribute of the vector of edge lengths in a "phylo" object in R such that the name of each edge is given by the formula "parent node #,daughter node #" or, if the daughter node is a tip, then "parent node #,daughter tip label". I'll repeat this hear for the future reference of me & the readers of this blog (if there are any left by the end of this entry):

> library(ape)
> set.seed(100)
> tree > X > # replace all node numbers for tips with their labels
> X[X[,2]%in%1:length(tree$tip),2] tree$tip[X[X[,2]%in%1:length(tree$tip),2]]
> # substitute the names of tree$edge.length for the rows of X
> names(tree$edge.length) > round(tree$edge.length,2)
11,12??12,t9??12,13??13,t4??13,t5??11,14??14,15??15,t2??15,16
??0.20?? 0.36?? 0.36?? 0.69?? 0.54?? 0.71?? 0.54?? 0.75?? 0.42
16,t10??16,17??17,t8??17,t7??14,18??18,t6??18,19??19,t3??19,t1
??0.17?? 0.77?? 0.88?? 0.55?? 0.28?? 0.49?? 0.93?? 0.35?? 0.95
> plot(tree,no.margin=T)
> edgelabels(round(tree$edge.length,2))
> nodelabels()

(We can see that the branch lengths of the tree, plotted as edge labels, line up exactly with the branch names in tree$edge.length. Cool.)

That's it.

Source: http://phytools.blogspot.com/2012/08/trick-to-name-edges-of-phylo-object-for.html

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