members {multiv}R Documentation

Cluster Memberships

Description

From a succession of agglomerations produced by a hierarchical routine in function `hierclust' or `hclust', determine cluster assignments of all objects, at all levels of the hierarchy.

Usage

members(a)

Arguments

a output produced by functions hierclust (or hclust or mclust).

Value

matrix of dimensions n by n-2 giving cluster assignments to the 2, 3, ...{} n-1 cluster partitions of the hierarchy. This corresponds to levels n-2 to 2. The observations correspond to the rows, and are in sequence, 1, 2, ...{}. Column j specifies which of the 2, 3, ...{} j-1 clusters each observation is associated with at the level j-1 of the agglomerative process. The two clusters which merge in going from level j-1 to j-2 are replaced in the j-2nd column with the lower of the two cluster sequence numbers.

Note

The time requirement of 'members' is O(n^3). Sample time for Sun SPARCstation 1, with 600 observations: 303 secs.

See Also

Functions hierclust, hclust produce the array containing the sequence of agglomerations which can be used as input for members.

Examples

data(iris)
iris <- as.matrix(iris[,1:4])
h <- hierclust(iris, method=2)
k <- members(h)