[GRASSLIST:593] Re: i.gensig and signature file

[Markus Neteler]

On Tue, Jul 01, 2003 at 10:51:28AM -0700, Daniel Victoria wrote:
> Hi all,
> 
> I'm trying to create a signature file using i.gensig.
> I aquiered the training sites with v.digit and
> converted them to raster. My raster file consist of 5
> small "clumps" with value 1 and the rest is null. When
> I run i.gensig I gue the message
> Signature 1 not positive definite
> and the signature file only contains # on the first
> line
> 
> What could be wrong?

Probably the traiing areas are to small or do not cover
the image channels?

You may try to use
i.gensigset
i.smap

instead which performs usually better than i.maxlik.

Markus