is.ultrametric {ape} | R Documentation

## Test if a Tree is Ultrametric

### Description

This function tests whether a tree is ultrametric using the distances from each tip to the root.

### Usage

    is.ultrametric(phy, ...)
    ## S3 method for class 'phylo'
    is.ultrametric(phy, tol = .Machine$double.eps^0.5, option = 1, ...)
    ## S3 method for class 'multiPhylo'
    is.ultrametric(phy, tol = .Machine$double.eps^0.5, option = 1, ...)

### Arguments

`phy` | an object of class `"phylo"` or `"multiPhylo"`.
`tol` | a numeric >= 0, variation below this value are considered non-significant.
`option` | an integer (1 or 2; see details).
`...` | arguments passed among methods.

### Details

The test is based on the distances from each tip to the root and a criterion: if `option = 1`, the criterion is the scaled range ((max - min/max)), if `option = 2`, the variance is used (this was the method used until ape 3.5). The default criterion is invariant to linear changes of the branch lengths.

### Value

a logical vector.

### Author(s)

Emmanuel Paradis

### See Also

`is.binary`, `.Machine`

### Examples

    is.ultrametric(rtree(10))
    is.ultrametric(rcoal(10))

[Package ape version 5.1 Index]