Computes the number of internal nodes with a single tip child.
Usage
ILnumber(tree, normalise = FALSE)
Value
The integer number of internal nodes with a single tip child.
Arguments
tree
a tree of class phylo or phylo4. The tree should be binary and rooted; if not it will be coerced into a binary rooted tree using multi2di, if possible.
## Find the IL number of a random tree with 10 tips:tree <- rtree(10)
plot(tree)
ILnumber(tree)
## and the normalised IL number:ILnumber(tree, normalise=TRUE)