[GRASS-user] Zonal Raster Statistics with overlapping polygons

Leonardo leonardo at mobygis.com
Fri Feb 24 02:48:42 PST 2017

Hi all,

I'm struggling to do Zonal Raster Statistics using v.rast.stats in GRASS 
This tool works neatly and fast, but seems it doesn't deal with 
overlapping polygons.

I'm using a polygon vector layer with overlapped polygons, I know, is not
topologically correct, but those polygons does't describe physical 
feature but
just some figurative mask for the statistics, therefore should exist 
and I want the statisics calculated over the whole polygons.

Using v.rast.stats with this vector layer the statistics seem to be 
only over the non overlapping part of the feature, I've also tried to import
the vector layer (originally was a shapefile) without build the topology,
but the results seem the same.

I've test also the QGIS ZonalStats plugin, and it works exactly how I want,
the statistics for each polygon are calculate for the whole polygon, is 
there a method
to do the same in GRASS GIS?

Have someone some hint, possibly smarter and faster than looping ever 
each feature
and then join each table?

Thanks in advance,

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