On Sat, Oct 19, 2013 at 5:20 PM, matteo poletti <[email protected]> wrote: > Hi Margherita, > > Thank you for your reply! > >> Da: Margherita Di Leo <[email protected]> >>Which kind of map is the base map? > > Well, shouldn't be the base map just a raster map which assigns the same > category to the cells that should be averaged together? > > >> If you compare the average you get from 2 base maps at different >> resolutions, you probably will get two different values. > > I'm sorry but I don't get the point.
In the case of different resolutions GRASS performs resampling on the fly which is nearest neighbor resampling. It is usually better to do that in a user controlled way, i.e. prepare the maps properly beforehand. > The base map I use is always at the same resolution (res=0.2), which is also > the resolution of the region. My problem is that I have a cover map with with > a different resolution (res=200) and if I use it as it is I get wrong result. > The workaround I found is to change the resolution of the cover map before > running r.average (r.mapcalc "rescaled_cover_map=original_cover_map") but > it's ugly. Right. Please see http://grasswiki.osgeo.org/wiki/Interpolation#Reinterpolation_of_.22filled.22_raster_maps_.28continuous_data.29_to_a_different_resolution -> Resampling of raster maps to finer resolution for better ways. Best Markus _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
