is.ultrametric: Test if a Tree is Ultrametric
Description
This function computes the distances from each tip to the root: if the
variance of these distances is null, the tree is considered as
ultrametric.Usage
is.ultrametric(phy, tol = .Machine$double.eps^0.5)
Value
a logical: TRUE
if the tree is ultrametric, FALSE
otherwise.Details
The default value for tol
is based on the numerical
characteristics of the machine Ris running on.