Re: st: use of a distance matrix for cluster analysis in STATA

[James Muller <james.muller@internode.on.net>]

(please nobody flame me here :)

Just out of curiosity, why don't you use something like R for the whole 
process - R's language treats the sort of data objects you'll be using 
more generally than Stata does, and it's probably a cleaner way to do 
everything, overall. Plus R is open source (i.e. no part of any 
clustering methods are a black box), gives you better control over 
handling missing values, and has generally a more active community 
involved in this sort of thing. You would also have the opportunity to 
modify the clustering methods if you like. A couple of other 
alternatives would be scilab or octave (matlab-like programs), or if 
you're feeling adventurous, use the GSL and implement the methods yourself.

Another reason to use R over Stata for this sort of thing, is that 
visualization is probably important to you, and R's visual functions 
walk on Stata's for this sort of thing (and most other things, I believe).

Cheers,
your local R advocate,
James






Jochen Siegele wrote:


> Dear all, thanks a lot for your help and comments. 
> We have a relatively small number of objects, around 20. 
> Hence the raw data matrix is a 1.4 mio x 20 matrix with binary data.
> By an external programme we have calculated a 20x20 distance matrix.
>
> After importing the 20x20 distance matrix into STATA, STATA seems to interpret the imported matrix as raw data matrix and not as a distance matrix.
> Hence STATA seems to calculate a further distance matrix based on the important distance matrix and does not seem be able to accept the imported matrix as a distance matrix. 
> Is there any possibility telling STATA that the imported matrix is a distance matrix and not a raw data matrix? 
> We use STATA 8.1 for our calculations.
>
> Thanks a lot for any help.
>
> Jochen Siegele
>
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