Computes the number of internal nodes with a single tip child.
ILnumber(tree, normalise = FALSE)Arguments
- tree
a tree of class
phyloorphylo4. The tree should be binary and rooted; if not it will be coerced into a binary rooted tree using multi2di, if possible.- normalise
option to normalise the result, default is
FALSE
Value
The integer number of internal nodes with a single tip child.
Examples
## Find the IL number of a random tree with 10 tips:
tree <- rtree(10)
plot(tree)
ILnumber(tree)
#> [1] 4
## and the normalised IL number:
ILnumber(tree, normalise=TRUE)
#> [1] 0.5