MDS_STRESS

- Sammon stress between dissimilarity matrices

    E = MDS_STRESS(Q,DS,D)

Input
Q	Indicator of the Sammon stress; Q = -2,-1,0,1,2
DS	Original distance matrix
D	Approximated distance matrix

Output
E	Sammon stress

Description

Computes the Sammon stress between the original distance matrix Ds  and the approximated distance matrix D, expressed as follows

    E = 1/(sum_{i<j} DS_{ij}^(q+2)) sum_{i<j} (DS_{ij} - D_{ij})^2 * DS_{ij}^q