Aren Cambre : > I am not getting any responses. :-) Am I doing something really dumb? Is > this the right forum for this kind of question?
This should be the right kind of forum, but maybe nobody has an idea about what could be wrong. Just a guess: maybe no points of the input vector fall into the current region that is used to write the output raster map? Markus M > Thanks, > Aren > > On Sun, Feb 13, 2011 at 8:02 AM, Aren Cambre <a...@arencambre.com> wrote: >> >> Maybe I could clarify. Here's the command: >> v.kernel --verbose input=master_grass7 output=master_grass7a_heatmap >> stddeviation=.0001 >> Here's the command output: >> STDDEV: 0.000100 >> RES: 200.000000 ROWS: 1000 COLS: 1000 >> Writing output raster map using smooth parameter=0.000100. >> Normalising factor=0.000000. >> Maximum value in output: 0.000000e+000. >> If I change stddeviation to 100, here's what I get: >> STDDEV: 100.000000 >> RES: 200.000000 ROWS: 1000 COLS: 1000 >> Writing output raster map using smooth parameter=100.000000. >> Normalising factor=64826.350188. >> Maximum value in output: 0.000000e+000. >> Either way, the resulting raster is a large salmon/pink square. I have no >> idea what I'm doing wrong. I've tried varying the stddeviation parameter >> from 100 to .0001 and some values in between, and I don't get anything >> different. Heck, I just now used 1000000 and .000001 and got nothing >> different. >> I was really hoping to make a high res heat map of these 2.5 million >> points and overlay on to a street map layer. >> Aren >> >> On Fri, Feb 11, 2011 at 9:45 PM, Aren Cambre <a...@arencambre.com> wrote: >>> >>> I am not clear how to get useful results out of v.kernel. I have a vector >>> layer imported from PostGIS that has about 2.5 million points. I want to >>> make a high density raster to show where these points are clustered. I can >>> get the vector layer to display in GRASS just fine, albeit without >>> attributes because of http://trac.osgeo.org/grass/ticket/1274. >>> It's not clear to me, based >>> on http://grass.fbk.eu/gdp/html_grass64/v.kernel.html, how you can get it to >>> do something besides make a big, pinkish (salmon-red?) square? >>> Aren > > > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user > > _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user