Rich Shepard wrote > On Tue, 20 Sep 2016, Helmut Kudrnovsky wrote: > >> If it is about raster reprojection, there are hints in the r.proj manual >> about region settings before applying r.proj. >> >> A simple way to do this is to check the projected bounds of the input map >> in the current location's projection using the -p flag. The -g flag >> reports the same thing, but in a form which can be directly cut and >> pasted >> into a g.region command. After setting the region in that way you might >> check the cell resolution with "g.region -p" then snap it to a regular >> grid with g.region's -a flag. E.g. g.region -a res=5 -p. Note that this >> is >> just a rough guide. >> >> A more involved, but more accurate, way to do this is to generate a >> vector >> "box" map of the region in the source location using v.in.region -d. This >> "box" map is then reprojected into the target location with v.proj. Next >> the region in the target location is set to the extent of the new vector >> map with g.region along with the desired raster resolution (g.region -m >> can be used in Latitude/Longitude locations to measure the geodetic >> length >> of a pixel). r.proj is then run for the raster map the user wants to >> reproject. In this case a little preparation goes a long way. > > Helmut, > > Thank you very much. This expansion of Micha's explanation is really > valuable and I greatly appreciate it. I wasn't aware of this need and > process the last time (years ago) I had a need to reproject data. Source > data in recent projects were all in the same projection and appropriate to > the area studied. > > Regards, > > Rich > _______________________________________________ > grass-user mailing list
> [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user It's copy /paste from the manual. So the manual is your best friend. ;-) ----- best regards Helmut -- View this message in context: http://osgeo-org.1560.x6.nabble.com/A-question-about-raster-map-resolutions-tp5286992p5287104.html Sent from the Grass - Users mailing list archive at Nabble.com. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
