This module is an interface to the C Clustering Library, a general purpose library implementing functions for hierarchical clustering (pairwise simple, complete, average, and centroid linkage), along with k-means and k-medians clustering, and 2D self-organizing maps. The library is distributed along with Cluster 3.0, an enhanced version of the famous Cluster program originally written by Michael Eisen while at Stanford University. The C clustering library was written by Michiel de Hoon. This module is a Perl wrapper for the C clustering library for cDNA microarray data, Copyright (C) 2002 Michiel Jan Laurens de Hoon.