Test for Binary Tree

Description

This function tests whether a phylogenetic tree is binary.

Usage

is.binary.tree(phy)

Arguments

Details

The test differs slightly whether the tree is rooted or not. An urooted tree is considered binary if all its nodes are of degree three (i.e., three edges connect to each node). A rooted tree is considered binary if all nodes (including the root node) have exactly two descendant nodes, so that they are of degree three expect the root which is of degree 2.

Value

is.binary.tree returns TRUE if tree is a fully binary phylogenetic tree, otherwise it returns FALSE.

Author(s)

Korbinian Strimmer (http://www.stat.uni-muenchen.de/~strimmer/)

See Also

is.rooted, is.ultrametric, multi2di

Examples

data("hivtree.newick") # example tree in NH format
tree.hiv <- read.tree(text = hivtree.newick)
is.binary.tree(tree.hiv)
plot(tree.hiv)