rare (version 0.1.2)

find.leaves: Find all descendant leaves of a node in an hclust tree

Description

The function recursively finds all leaves that are descendants of a node in an hclust tree.

Usage

find.leaves(ind, merge)

Value

Returns a sequence of indices for descendant leaves in the leaf set {1, ..., p}. Unlike the notation used in ind, we use positive integers to denote leaves here.

Arguments

ind

Index of the tree node. For an hclust tree of p leaves, -j denotes the jth leaf and k denotes the interior node formed at the kth merging in constructing the tree. The range of ind is {-1, ..., -p, 1,..., p-1} where p-1 is the number of interior nodes.

merge

A (p-1)-by-2 matrix that encodes the order of mergings in constructing the tree. merge uses the same notation for nodes and mergings in an hclust object. See hclust for details.

Examples

if (FALSE) {
hc <- hclust(dist(USArrests), "ave")
# Descendant leaves of the 10th leaf (should be iteself)
find.leaves(-10, hc$merge)

# Descendant leaves of the 10th interior node
find.leaves(10, hc$merge)

# Descendant leaves of the root (should be all leaves)
ind_root <- nrow(hc$merge)
all.equal(find.leaves(ind_root, hc$merge), hc$order)
}