\HeaderA{rect.hclust}{Draw Rectangles Around Hierarchical Clusters}{rect.hclust}
\keyword{aplot}{rect.hclust}
\keyword{cluster}{rect.hclust}
\begin{Description}\relax
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.
\end{Description}
\begin{Usage}
\begin{verbatim}
rect.hclust(tree, k = NULL, which = NULL, x = NULL, h = NULL,
            border = 2, cluster = NULL)
\end{verbatim}
\end{Usage}
\begin{Arguments}
\begin{ldescription}
\item[\code{tree}] an object of the type produced by \code{hclust}.
\item[\code{k, h}] Scalar. Cut the dendrogram such that either exactly
\code{k} clusters are produced or by cutting at height \code{h}.
\item[\code{which, x}] A vector selecting the clusters around which a
rectangle should be drawn. \code{which} selects clusters by number
(from left to right in the tree), \code{x} selects clusters
containing the respective horizontal coordinates. Default is
\code{which = 1:k}.
\item[\code{border}] Vector with border colors for the rectangles.
\item[\code{cluster}] Optional vector with cluster memberships as returned by
\code{cutree(hclust.obj, k = k)}, can be specified for efficiency if
already computed.
\end{ldescription}
\end{Arguments}
\begin{Value}
(Invisibly) returns a list where each element contains a vector of
data points contained in the respective cluster.
\end{Value}
\begin{SeeAlso}\relax
\code{\LinkA{hclust}{hclust}}, \code{\LinkA{identify.hclust}{identify.hclust}}.
\end{SeeAlso}
\begin{Examples}
\begin{ExampleCode}
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
\end{ExampleCode}
\end{Examples}

