Multidimensional Scaling Techniques

["Bert, Jacobs" <b.jacobs@pandora.be>]

Dear ,

I'm a marketing researcher and I have the following problem.

I've calculated the following cross-elasticity matrix for several
competitive brands:

                Brand A Brand B Brand C Brand D Brand E

Brand A         -3.80           1.70            1.87            1.11            
1.68
Brand B 1.50            -3.34           1.30            1.60            1.10
Brand C         1.10            0.68            -3.18           1.00            
0.92
Brand D 0.70            1.14            0.92            -3.53           0.46
Brand E 0.90            0.70            0.97            0.50            -3.42

I've heard somewhere that I can use a Multidimensional Scaling Technique to
discover underlying dimensions of this matrix.

The problem is that I don't know
1) if I should transform this matrix into a symmetric matrix and how the
outcome should look like.
2) Which MDS method I should use (Indscal, Alscal,IsoMDS)
3) If this method exists in an S-Plus library and how I can retrieve it.
4) How I should organize my data in S-Plus (as frame, matrix, array?) to
perform the analyses.

Thank you very much for your input.

Best Regards,

Bert Jacobs