[R] results from sammon()

[Prof Brian Ripley]

On Wed, 20 Apr 2005, Domenico Cozzetto wrote:

> I'm trying to get a two dimensional embedding of some data using different
> meythods, among which princomp(), cmds(), sammon() and isoMDS(). I have a

What is cmds()?  There is cmdscale(), but if you have the data (needed to 
use PCA) then classical scaling and PCA are the same thing.

> problem with sammon() because the coordinates I get are all equal to NA.
> What does it mean? Why the method fails in finding the coordinates? Can I do
> anything to get some meaningful results?

We have no idea. Please read the posting guide and supply some useful 
information and preferably a reproducible example.  One issue is which 
package sammon() came from.

One possible hint if this is sammon() from MASS is to use a different 
starting configuration.

> PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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