[S] sammon() function question

Bill Shipley (bshipley@courrier.usherb.ca)
Tue, 24 Nov 1998 11:21:55 -0500


The Venables & Ripley MASS library includes a function called sammon().
This function performs a nonlinear mapping of data from a higher dimensional
space into a smaller (eg. 2) dimensional space. I give the reference for
this at the end of the posting.
My question concerns the relationship of this to non-metric multidimensional
scaling. Both seem to do somewhat the same thing, but I don't know how
(exactly) they differ. Is one superior to the other under certain conditions?
Any leads about the sammon algorithm, or its comparison to other methods, is
appreciated.
Reference: Sammon, J.W. 1969. A nonlinear mapping for data structure
analysis. IEEE Trans. on Computers C-18, 401-409.

Thanks.
Bill Shipley
Departement de Biologie
Universite de Sherbrooke
Sherbrooke (Quebec)
CANADA J1K 2R1
bshipley@courrier.USherb.ca
voix: 819-821-8000 poste 2079
telecopieur: 819-821-8049
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