| % File src/library/stats/man/identify.hclust.Rd |
| % Part of the R package, https://www.R-project.org |
| % Copyright 1995-2007 R Core Team |
| % Distributed under GPL 2 or later |
| |
| \name{identify.hclust} |
| \alias{identify.hclust} |
| \title{Identify Clusters in a Dendrogram} |
| \description{ |
| \code{identify.hclust} reads the position of the graphics pointer when the |
| (first) mouse button is pressed. It then cuts the tree at the |
| vertical position of the pointer and highlights the cluster containing |
| the horizontal position of the pointer. Optionally a function is |
| applied to the index of data points contained in the cluster. |
| } |
| \usage{ |
| \method{identify}{hclust}(x, FUN = NULL, N = 20, MAXCLUSTER = 20, DEV.FUN = NULL, |
| \dots) |
| } |
| \arguments{ |
| \item{x}{an object of the type produced by \code{hclust}.} |
| \item{FUN}{(optional) function to be applied to the index numbers of |
| the data points in a cluster (see \sQuote{Details} below).} |
| \item{N}{the maximum number of clusters to be identified.} |
| \item{MAXCLUSTER}{the maximum number of clusters that can be produced |
| by a cut (limits the effective vertical range of the pointer). } |
| \item{DEV.FUN}{(optional) integer scalar. If specified, the |
| corresponding graphics device is made active before \code{FUN} is |
| applied.} |
| \item{\dots}{further arguments to \code{FUN}.} |
| } |
| \details{ |
| By default clusters can be identified using the mouse and an |
| \code{\link{invisible}} list of indices of the respective data points |
| is returned. |
| |
| If \code{FUN} is not \code{NULL}, then the index vector of data points |
| is passed to this function as first argument, see the examples |
| below. The active graphics device for \code{FUN} can be specified using |
| \code{DEV.FUN}. |
| |
| The identification process is terminated by pressing any mouse |
| button other than the first, see also \code{\link{identify}}. |
| } |
| \value{ |
| Either a list of data point index vectors or a list of return values |
| of \code{FUN}. |
| } |
| \seealso{ |
| \code{\link{hclust}}, |
| \code{\link{rect.hclust}} |
| } |
| \examples{\dontrun{ |
| require(graphics) |
| |
| hca <- hclust(dist(USArrests)) |
| plot(hca) |
| (x <- identify(hca)) ## Terminate with 2nd mouse button !! |
| |
| hci <- hclust(dist(iris[,1:4])) |
| plot(hci) |
| identify(hci, function(k) print(table(iris[k,5]))) |
| |
| # open a new device (one for dendrogram, one for bars): |
| dev.new() # << make that narrow (& small) |
| # and *beside* 1st one |
| nD <- dev.cur() # to be for the barplot |
| dev.set(dev.prev()) # old one for dendrogram |
| plot(hci) |
| ## select subtrees in dendrogram and "see" the species distribution: |
| identify(hci, function(k) barplot(table(iris[k,5]), col = 2:4), DEV.FUN = nD) |
| }} |
| \keyword{cluster} |
| \keyword{iplot} |