R help - Mar 2001 - Kohonen's SOM in R?

Is there an implementation of the SOM ('Self Organizing Map') procedure
in
R ? 

I am aware of the implementations of Sammon mapping, multidimensional 
scaling and, somewhat peripherally, principal curves and projection 
pursuit ..  but not SOM per se as far as I can see. Am I missing 
something?


---------------------

for anyone interesed in SOM
I found Samuel Kaski's thesis "Data exploration using self-organizing 
maps" fairly accessible
http://www.cis.hut.fi/~sami/thesis.ps

and there is a wealth of material at

http://www.cis.hut.fi/research/som-research/som.shtml


John Aitchison
-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

On Thu, 1 Mar 2001, John Aitchison wrote:
>
> Is there an implementation of the SOM ('Self Organizing Map')
procedure in
> R ?
>
> I am aware of the implementations of Sammon mapping, multidimensional
> scaling and, somewhat peripherally, principal curves and projection
> pursuit ..  but not SOM per se as far as I can see. Am I missing
> something?
Not that I know of, although some pure S code was mentioned on S-news once.
It was very slow when I tried it.  You might like to check that list's
archive:

http://www.biostat.wustl.edu/hyperlists/s-news/199906/msg00061.html

The link there is dead, but the code is on

http://www.biostat.wustl.edu/hyperlists/s-news/199906/msg00062.html


I once wrote an R interface to SOM-PAK (via system).  Something like that
is on my TODO list.  However, SOM is just an algorithm whose fine details
are not really documented except via the group's programs.  One could build
an R interface to their C code, but as it would be for `scientific
purposes' only, it would probably not meet your needs.

-- 
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)
1 South Parks Road,                     +44 1865 272860 (secr)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._