ape (version 1.2-2)

balance: Balance of a Dichotomous Phylogenetic Tree

Description

This function computes the balance of a phylogenetic tree, that is for each node of the tree the numbers of descendants (i.e. tips) on each of its daughter-branch. The tree must be fully dichotomous.

Usage

balance(phy)

Arguments

phy
an object of class "phylo".

Value

  • a numeric matrix with two columns and one row for each node of the tree. The columns give the numbers of descendants on each daughter-branches (the order of both columns being arbitrary). If the phylogeny phy has an element node.label, this is used as rownames for the returned matrix; otherwise the numbers (of mode character) of the matrix edge of phy are used as rownames.

References

For a discussion on tree balance: Aldous, D. J. (2001) Stochastic models and descriptive statistics for phylogenetic trees, from Yule to today. Statistical Science, 16, 23--34.