[GRASS-user] i.pca gives error

[Markus Neteler]

On Fri, Apr 4, 2014 at 1:47 PM, Martin van Brakel
<m.l.vanbrakel at gmail.com> wrote:
> Hi list,
>
> i am processing plenty of modis subsets into a group called "pca"
>
> when using WinGRASS it gives an error
>
> GRASS 7.0.svn> i.pca --overwrite input=pca output_prefix=_msub
> Computing covariance matrix...
>  100%
> ERROR: No non-null values
> GRASS 7.0.svn>

Did you set the computational region to the map beforehand?

g.region rast=pca -p

then
i.pca ...

See also:
http://grasswiki.osgeo.org/wiki/Computational_region
Since we currently have issues on the server (slow), see also the wiki
mirror at:
http://grass.fsv.cvut.cz/wiki-mirror/index.php/Computational_region

hope this helps
Markus