symNodesI: Calculation of the symmetry nodes index for rooted binary...

In treebalance: Computation of Tree (Im)Balance Indices

Description

This function calculates the symmetry nodes index SNI(T) for a given rooted binary tree T. SNI(T) is defined as the number of inner vertices v that are not symmetry nodes, i.e. the two pending subtrees rooted at the children of v do not have the same tree shape.

For n=1 the function returns SNI(T)=0 and a warning.

Usage

symNodesI(tree)

Arguments

tree	A rooted binary tree in phylo format.

Value

symNodesI returns the symmetry nodes index of the given tree.

Author(s)

Sophie Kersting

References

S. J. Kersting and M. Fischer. Measuring tree balance using symmetry nodes — A new balance index and its extremal properties. Mathematical Biosciences, page 108690, 2021. ISSN 0025-5564. doi:https://doi.org/10.1016/j.mbs.2021.108690

Examples

tree <- ape::read.tree(text="((((,),),(,)),(((,),),(,)));")
symNodesI(tree)

treebalance documentation built on Oct. 17, 2021, 5:06 p.m.