cophylo plot doesn't produce trees, only two vertical lines

[mprodriguezp]

Hi,

I've been trying to use the coplot function to compare two phylogenetic trees (both have the same 522 tips), but the plot only shows two vertical black lines like shown below. I tried saving the file with a big size to see if it was a matter of plot margins in R, but it's not.

Below is the code I've been using. Since both trees share the same tips (I double-checked this), I created the association matrix with a dataframe using the tips of one tree. I also double-checked that both trees are phylo objects and the obj summary looks good, and I tried both rotation T or F, but I got the same result.

library(ape)
library(phytools)


tree200 <- read.tree("./withchunk200/varistes.chunk200.nwk")
tree92 <- read.tree("./withchunk92/varsites.chunk92.nwk")

assoc <- data.frame("t200" = tree200$tip.label,
                    "t92" = tree200$tip.label)

obj<-cophylo(tree200,tree92,rotate=FALSE,assoc=assoc)
obj<-cophylo(tree200,tree92,assoc=assoc)
summary(obj)
plot(obj)

Could you please tell me what am I doing wrong, please? I am new in phytools, but I think I am doing the basic stuff that the code needs according to previous examples in the blog and in other websites.

Thanks in advance,
Maria