# is.ultrametric

From ape v2.6-3
0th

Percentile

##### Test if a Tree is Ultrametric

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.

Keywords
utilities
##### Usage
is.ultrametric(phy, tol = .Machine\$double.eps^0.5)
##### Arguments
phy
an object of class "phylo".
tol
a numeric >= 0, variation below this value are considered non-significant (see details).
##### Details

The default value for tol is based on the numerical characteristics of the machine R is running on.

##### Value

• a logical: TRUE if the tree is ultrametric, FALSE otherwise.

is.binary.tree, .Machine