R: Distributions of tips consistent with a partition pair

NPartitionPairs {TreeTools} | R Documentation

## Distributions of tips consistent with a partition pair

### Description

`NPartitionPairs()` calculates the number of terminal arrangements matching a specified configuration of two splits.

### Usage

    NPartitionPairs(configuration)

### Arguments

`configuration` | Integer vector of length four specifying the number of terminals that occur in both (1) splits A1 and A2; (2) splits A1 and B2; (3) splits B1 and A2; (4) splits B1 and B2.

### Details

Consider splits that divide eight terminals, labelled A to H.

Bipartition 1: | ABCD:EFGH | A1 = ABCD | B1 = EFGH
Bipartition 2: | ABE:CDFGH | A2 = ABE | B2 = CDFGH

This can be represented by an association matrix:

| A2 | B2
A1 | AB | C
B1 | E | FGH

The cells in this matrix contain 2, 1, 1 and 3 terminals respectively; this four-element vector (`c(2, 1, 1, 3)`) is the `configuration` implied by this pair of bipartition splits.

### Value

The number of ways to distribute `sum(configuration)` taxa according to the specified pattern.

### Author(s)

Martin R. Smith (martin.smith@durham.ac.uk)

### Examples

    NPartitionPairs(c(2, 1, 1, 3))

[Package TreeTools version 1.3.1 Index]