For cropping, see also a new addon module called r.clip which clips according the computational region while respecting mask and the *original* raster resolution:
https://grass.osgeo.org/grass72/manuals/addons/r.clip.html Testing and feedback welcome. Vaclav On Tue, Sep 26, 2017 at 10:35 AM, Moritz Lennert < [email protected]> wrote: > On 26/09/17 16:17, Moritz Lennert wrote: > >> On 26/09/17 15:57, Marco Alicera wrote: >> >>> Dear list, >>> I am trying to crop a raster map into a smaller area, but I am failing. >>> >>> This wiki page link <https://grasswiki.osgeo.org/wiki/Cropping_maps> is >>> quite clear: >>> "Make boundary into mask using r.mask >>> <https://grass.osgeo.org/grass72/manuals/r.mask.html> then copy raster >>> source to new map (g.copy >>> <https://grass.osgeo.org/grass72/manuals/g.copy.html>). All cells >>> outside of the mask will be omitted from the new copy." >>> >>> r.mask vector=myarea >>> g.copy --overwrite raster=OldRasterWithBigArea,NewRasterWithSmallArea >>> r.mask -r >>> >>> I expected all cell outside were not going to be omitted, but replaced >>> by NULL. >>> >> >> I'm not sure I understand your last sentence, but AFAIK, the wiki info >> is wrong. g.copy works directly on the files and ignores mask and region >> settings. In your example, OldRasterWithBigArea and >> NewRasterWithSmallArea should be strictly identical. >> >> You need to use r.mapcalc "new = old" while the mask is set to get a >> raster with everything outside the mask set to NULL. >> > > I've rewritten the wiki page to try to make things clearer. > > > Moritz > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user >
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