count_tips_per_node {castor}

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")