[GRASS-user] Signature not invertible

[joel dinis]

Hello list,

I'm with a problem running the i.gensig.
I do:

i.gensig trainingmap=areasraster at Portugal_9
group=grupo at Portugal_9subgroup=subgrupo
signaturefile=assinaturascomareas

where areasrastes has 4 classes.
The *r.stats -c input=areasraster at Portugal_9* is
1 92
2 234
3 2434
4 3016
* 287024

And I get the following:

Finding training classes...
4 classes found
Calculating class means...
Calculating class covariance matrices...
Signature 1 not invertible
Signature 2 not invertible
Signature 3 not invertible
Signature 4 not invertible
i.gensig complete.

My question is: do I need any package to deal with
matrix calculus? If so, each? If not, what is wrong
here?

Thanks in advance
JD
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/grass-user/attachments/20100415/e2a6bb8a/attachment.html