ape (version 4.0)

ewLasso: Incomplete distances and edge weights of unrooted topology

Description

This function implements a method for checking whether an incomplete set of distances satisfy certain conditions that might make it uniquely determine the edge weights of a given topology, T. It prints information about whether the graph with vertex set the set of leaves, denoted by X, and edge set the set of non-missing distance pairs, denoted by L, is connected or strongly non-bipartite. It then also checks whether L is a triplet cover for T.

Usage

ewLasso(X, phy)

Arguments

X

a distance matrix.

phy

an unrooted tree of class "phylo".

Value

NULL, the results are printed in the console.

Details

Missing values must be represented by either NA or a negative value.

This implements a method for checking whether an incomplete set of distances satisfies certain conditions that might make it uniquely determine the edge weights of a given topology, T. It prints information about whether the graph, G, with vertex set the set of leaves, denoted by X, and edge set the set of non-missing distance pairs, denoted by L, is connected or strongly non-bipartite. It also checks whether L is a triplet cover for T. If G is not connected, then T does not need to be the only topology satisfying the input incomplete distances. If G is not strongly non-bipartite then the edge-weights of the edges of T are not the unique ones for which the input distance is satisfied. If L is a triplet cover, then the input distance matrix uniquely determines the edge weights of T. See Dress et al. (2012) for details.

References

Dress, A. W. M., Huber, K. T., and Steel, M. (2012) `Lassoing' a phylogentic tree I: basic properties, shellings and covers. Journal of Mathematical Biology, 65(1), 77--105.