[R] MDS with missing data? (change topic -> isomap)

context grey mobygeek at yahoo.com
Thu Jun 15 22:05:40 CEST 2006


Thanks for the isoMDS pointer.   I found one
implementation
of isomap at  
  http://user.cs.tu-berlin.de/~astro/kmethods
though the web page suggests the code may be immature.


--- Jari Oksanen <jarioksa at sun3.oulu.fi> wrote:

> On Thu, 2006-06-15 at 07:13 +0300, Jari Oksanen
> wrote:
> 
> 
> > >
> > > 1) use nonmetric/gradient descent MDS which
> seems to
> > > allow missing data, or
> > >
> > Not the isoMDS function in MASS. if N(N-1) is a
> problem, then nonmetric 
> > MDS may not be the solution.
> 
> Sorry for the wrong information: isoMDS does handle
> NA. I remembered old
> times when I looked at the issue, but isoMDS changed
> since. Fine work!
> 
> cheers, jari oksanen
> -- 
> Jari Oksanen -- Dept Biology, Univ Oulu, 90014 Oulu,
> Finland
> email jari.oksanen at oulu.fi, homepage
> http://cc.oulu.fi/~jarioksa/
> 
>



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