Node labels on circular phylogenetic tree

Question

I am trying to create circular phylogenetic tree. I have this part of code:

fit<- hclust(dist(Data[,-4]), method = "complete", members = NULL)

nclus= 3
color=c('red','blue','green')
color_list=rep(color,nclus/length(color))
clus=cutree(fit,nclus)

plot(as.phylo(fit),type='fan',tip.color=color_list[clus],label.offset=0.2,no.margin=TRUE, cex=0.70, show.node.label = TRUE)

And this is result:

Also I am trying to show label for each node and to color branches. Any suggestion how to do that?

Thanks!

Answer 1

When you say "color branches" I assume you mean color the edges. This seems to work, but I have to think there's a better way.

Using the built-in mtcars dataset here, since you did not provide your data.

plot.fan <- function(hc, nclus=3) {
  palette <- c('red','blue','green','orange','black')[1:nclus]
  clus    <-cutree(hc,nclus)
  X <- as.phylo(hc)
  edge.clus <- sapply(1:nclus,function(i)max(which(X$edge[,2] %in% which(clus==i))))
  order     <- order(edge.clus)
  edge.clus <- c(min(edge.clus),diff(sort(edge.clus)))
  edge.clus <- rep(order,edge.clus)
  plot(X,type='fan',
       tip.color=palette[clus],edge.color=palette[edge.clus],
       label.offset=0.2,no.margin=TRUE, cex=0.70)  
}
fit <- hclust(dist(mtcars[,c("mpg","hp","wt","disp")]))
plot.fan(fit,3); plot.fan(fit,5)

Regarding "label the nodes", if you mean label the tips, it looks like you've already done that. If you want different labels, unfortunately, unlike plot.hclust(...) the labels=... argument is rejected. You could experiment with the tiplabels(....) function, but it does not seem to work very well with type="fan". The labels come from the row names of Data, so your best bet IMO is to change the row names prior to clustering.

If you actually mean label the nodes (the connection points between the edges, have a look at nodelabels(...). I don't provide a working example because I can't imagine what labels you would put there.