The file example.c contains a small C program that calls the routines in the
C Clustering Library. To compile this program, type "make".

If you want to call the routines in the C Clustering Library, in most cases the
file data.c is not needed. This file contains code to communicate between the
GUI program Cluster 3.0 and the routines in the C Clustering Library. For your
own program, you only need cluster.c and the corresponding header file
cluster.h. See chapter 10 in the manual for more information on
compiling and linking the C Clustering Library.