The rasterizing method gives comparable performances to ArcGIS. I confirm that it does the same. The bottleneck is the r.univar limitation to CELL. I have to investigate why, as it is based on r.stats which works with DCELL/FCELL too
The final join would be an improvement respect to Zonal Statistics in ArcGIS which simply produce a dbf with OIDs from polygon IDs but doesn't merge it into the original vectorial. 2009/2/19 Markus Metz <[email protected]>: > > > Markus Neteler wrote: >> >> On Thu, Feb 19, 2009 at 2:20 PM, G. Allegri <[email protected]> wrote: >> >>> >>> Thanks for the ideas. >>> I've just tried Starspan but it's performance is still too slow. I've >>> let it run for 15 minutes... >>> >> >> Can you please try GRASS 7? >> grass70/scripts/v.rast.stats/v.rast.stats.py >> > > grass70/scripts/v.rast.stats/v.rast.stats.py also uses r.mapcalc in every > pass: > > for i in cats: > ... > grass.mapcalc("MASK = if(...) > > if v.rast.stats is faster in grass7, then probably because of improved > raster libs. A speed increase from >5 hours to 40 seconds is unlikely since > grass.mapcalc is still called 1793 times (assuming each area has a unique > category) for a region with 4415x6632 cells... > > _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
