cutree                 package:stats                 R Documentation

Cut a tree into groups of data

Description:

     Cuts a tree, e.g., as resulting from 'hclust', into several groups
     either by specifying the desired number(s) of groups or the cut
     height(s).

Usage:

     cutree(tree, k = NULL, h = NULL)

Arguments:

    tree: a tree as produced by 'hclust'. 'cutree()' only expects a
          list with components 'merge', 'height', and 'labels', of
          appropriate content each.

       k: an integer scalar or vector with the desired number of groups

       h: numeric scalar or vector with heights where the tree should
          be cut.

     At least one of 'k' or 'h' must be specified, 'k' overrides 'h' if
     both are given.

Value:

     'cutree' returns a vector with group memberships if 'k' or 'h' are
     scalar, otherwise a matrix with group memberships is returned
     where each column corresponds to the elements of 'k' or 'h',
     respectively (which are also used as column names).

References:

     Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) _The New S
     Language_. Wadsworth & Brooks/Cole.

See Also:

     'hclust', 'dendrogram' for cutting trees themselves.

Examples:

     hc <- hclust(dist(USArrests))

     cutree(hc, k=1:5)#k = 1 is trivial
     cutree(hc, h=250)

     ## Compare the 2 and 3 grouping:
     g24 <- cutree(hc, k = c(2,4))
     table(g24[,"2"], g24[,"4"])

