Using phylomorphospace3d to plot 3D traitgrams

I realized after creating the three dimensional phylomorphospace function (phylomorphospace3d, described here) that one neat use of this function would be to do three dimensional traitgrams. That is, a projection of the tree into a space defined by time on one axis, and phenotype (in this case) on the other two.

This is relatively easy to do. This is because we've set up phylomorphospace3d to either estimate ancestral states or take them as input. To create a traitgram/phenogram - we just need to first estimate ancestral states for two characters, and then also compute the heights of internal and terminal nodes as our third "trait" (time from the root of the tree).

Both of these tasks are straightforward to accomplish. First, to estimate ancestral nodes for two characters encoded as columns in matrix X, we just do:

> require(phytools)
> A<-apply(X,2,function(x,tree) anc.ML(tree,x)$ace,tree=tree)

Then, we can compute the heights of internal and terminal nodes and attach them as columns in X and A, respectively.

> X<-cbind(X,diag(vcv(tree))[rownames(X)])
> A<-cbind(A,nodeHeights(tree)[match(rownames(A)[1:nrow(A)], tree$edge)])
> colnames(X)[3]<-colnames(A)[3]<-"time"

The final step, of course, just names our new trait axis what it is "time" since the root of the tree. With these parts, we can now use the new function phylomorphospace3d to plot our 3D traitgram.

I have built the steps above into the wrapper, fancyTree. To try it, just download the latest versions of the code for fancyTree (here) and phylomorphospace3d (here), load the source, and give it a try. The code below also uses the new simulation function sim.corrs, described here, but not yet a part of phytools.

> source("fancyTree.R")
> source("phylomorphospace3d.R")
> source("sim.corrs.R")
> require(phytools)
> tree<-pbtree(n=100,scale=10)
> X<-sim.corrs(tree,vcv=matrix(c(1,0.75,0.75,1),2,2))
> fancyTree(tree,type="traitgram3d",X)

And here's the result:


Cool.