Table 3. Values of the validity indices by different number of clusters for SDS2.

c	XB	TS	PBMF	MPC
2	0.08256631	4.213788	257.2904	0.9480826
3	0.85765530	43.048094	30203.7867	0.6795931
4	0.42083833	22.494335	42228.4537	0.7041015
5	3.36639018	177.540583	70887.5026	0.4275838
6	2.65760351	146.300871	45277.8600	0.4881886