R: Count descending tips.

count_tips_per_node {castor} | R Documentation

## Count descending tips.

### Description

Given a rooted phylogenetic tree, count the number of tips descending (directy or indirectly) from each node.

### Usage

    count_tips_per_node(tree)

### Arguments

`tree` | A rooted tree of class "phylo". The root is assumed to be the unique node with no incoming edge.

### Details

The asymptotic time complexity of this function is O(Nedges), where Nedges is the number of edges.

### Value

An integer vector of size Nnodes, with the i-th entry being the number of tips descending (directly or indirectly) from the i-th node.

### Author(s)

Stilianos Louca

### See Also

`get_subtree_at_node`

### Examples

    # generate a tree using a simple speciation model
    tree = generate_random_tree(list(birth_rate_intercept=1),max_tips=1000)$tree

    # count number of tips descending from each node
    tips_per_node = count_tips_per_node(tree);

    # plot histogram of tips-per-node
    barplot(table(tips_per_node[tips_per_node<10]), xlab="# tips", ylab="# nodes")

[Package castor version 1.3.4 Index]