# rect.hclust: Draw Rectangles Around Hierarchical Clusters

## Description

Draws rectangles around the branches of a dendrogram highlighting the
corresponding clusters. First the dendrogram is cut at a certain
level, then a rectangle is drawn around selected branches.

## Usage

rect.hclust(tree, k = NULL, which = NULL, x = NULL, h = NULL,
border = 2, cluster = NULL)

## Arguments

tree

an object of the type produced by `hclust`

.

k, h

Scalar. Cut the dendrogram such that either exactly
`k`

clusters are produced or by cutting at height `h`

.

which, x

A vector selecting the clusters around which a
rectangle should be drawn. `which`

selects clusters by number
(from left to right in the tree), `x`

selects clusters
containing the respective horizontal coordinates. Default is
`which = 1:k`

.

border

Vector with border colors for the rectangles.

cluster

Optional vector with cluster memberships as returned by
`cutree(hclust.obj, k = k)`

, can be specified for efficiency if
already computed.

## Value

(Invisibly) returns a list where each element contains a vector of
data points contained in the respective cluster.

## Examples

# NOT RUN {
require(graphics)
hca <- hclust(dist(USArrests))
plot(hca)
rect.hclust(hca, k = 3, border = "red")
x <- rect.hclust(hca, h = 50, which = c(2,7), border = 3:4)
x
# }