Nikos Alexandris a écrit : > > Funny, I am "stuck" as on how to (re-)define in layer 2 the "cat" > > column with > > unique categories for each (internal) feature id. There is nothing > > that > > helps-out towards this (simple?) task in the manuals (v.to.db).
Vincent Bain wrote: > this should do the job: > v.category op=add layer=2 type=centroid > then > v.to.db type=centroid option=cat Thank you Vincent. I think I've tried exactly that but it fails. It'll work only by creating a *new* vector map... Otherwise, it wont work (at least from what I've tried in G7). So, the process could be (given the shapefile provided by Lucien ): # import shapefil v.in.ogr dsn=test_polygones.shp out=polygons # create a new layer 2 v.db.addtable polygons layer=2 # check... v.db.connect polygons -p v.db.select polygons v.db.select polygons layer=2 # add unique cats -- this will not work if "out=" is not defined! v.category polygons option=add layer=2 type=centroid out=polygons_tmp v.to.db polygons_tmp type=centroid option=cat layer=2 col=cat # get stats for cats-wide stats for layer 1, that is only one cat! v.rast.stats -c vector=polygons_tmp raster=RandomRaster column_prefix=rr # get stats for cats in layer 2, that is for all different cats! v.rast.stats -c vector=polygons_tmp raster=RandomRaster column_prefix=rr2 layer=2 #...unfortunately, this last step in uploading stats in to layer 2, fails in G7 :-( # it works in G64! -- note different parameter naming: "colprefix=" v.build polygons_tmp v.rast.stats -c vector=polygons_tmp layer=2 raster=RandomRaster colprefix=rr2 Regards, Nikos _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
