On Fri, Dec 6, 2013 at 1:17 PM, Blumentrath, Stefan <stefan.blumentr...@nina.no> wrote: > Hi > > Maybe it is not of importance, because no one else would use such extreme > settings, but in case someone considers it as a bug: > > I was testing a bit with v.outlier in GRASS 7 on dense LiDAR data (~4 points > per m2). > > When I use a very low Tykhonov regularization parameter (lambda_i) of > 0.0000000000000000001 and rather short spline steps (1.5) at 0.5m resolution > I get an error-message: > > “Decomposition failed at row 16499 and col 0”
I found similar errors with very small lambda values, i guess it's some floating point precision limit. It seems that lambda should not be much smaller than 0.0001. For v.outlier, I would leave lambda at the default and rather use shorter spline steps, if you want to fine-tune the results. Markus M _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev