On Tue, Jun 26, 2018 at 9:53 AM, Nikos Alexandris <n...@nikosalexandris.net> wrote: > > * Markus Metz <markus.metz.gisw...@gmail.com> [2018-06-25 08:29:45 +0200]: > > [..] > >> The resolution is a bit wrong, it is 0.008333333300000 but should be >> 0.008333333333333, i.e. exactly 30 arc-seconds. This can be solved with the >> -a flag of r.in.gdal, or after import with r.region -a. >> >> The message >> >>> 360 degree EW extent is exceeded by 0.999827 cells >> >> >> will change to >> >>> 360 degree EW extent is exceeded by 1 cells >> >> >> but will not go away, because 360 degree EW extent is exceeded in the input >> data, the first and last column cover the same geographical area. You can >> change your current region to chop of e.g. the first column: set the region >> to the raster, then modify the current region with g.region w=179:59:45W -p >> and use this region for further processing. > > > I guess this is worth being documented in the manual of the add-on.
This is a universal problem applying to various raster data in latlong. The first issue, 30 sec represented as 0.008333333300000 instead of 0.008333333333333 is solved by r.in.gdal -a. The second problem, this extra column responsible that 360 degree EW extent is exceeded by 1 cell can be solved by setting the current region accordingly. This is also a universal problem. Maybe the manual of r.in.gdal could include a hint about how to do this. Generally, users are encouraged to inspect the output of r.info after importing raster data to check if everything is as expected. > Would > it also make sense to let the module attempt to perform this "correction"? If you refer to i.nightlights.intercalibration, I would say no, because it is a more general issue not restricted to DMSP-OLS nightlight data. Even more general, the current region as set by the user is used for raster processing (with a very few exceptions). Markus M
_______________________________________________ grass-user mailing list grass-user@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/grass-user