The use of r.external makes a lot of sense when dealing with very large files. Does the use of "external" files work as expected in all of the new t.* modules?
Thanks, Dylan On Wed, Oct 7, 2015 at 12:09 PM, Markus Neteler <[email protected]> wrote: > On Wed, Oct 7, 2015 at 12:55 PM, Blumentrath, Stefan > <[email protected]> wrote: > ... > > My suggestion is to not use PostGIS for big rasters, unless you have to, > > because you want to use the data in a specific application for example. > > Note r.external and r.external.out of GRASS GIS 7 for avoiding data > duplication: > > https://grass.osgeo.org/grass70/manuals/r.external.html > https://grass.osgeo.org/grass70/manuals/r.external.out.html > > Here an example: > > # register (rather than import) a GeoTIFF file in GRASS GIS: > r.external input=terra_lst1km20030314.LST_Day.tif output=modis_celsius > > # define output directory for files resulting from subsequent calculations: > r.external.out directory=$HOME/gisoutput/ format="GTiff" > > # perform calculations (here: extract pixels > 20 deg C) > # store output directly as GeoTIFF file, hence add the .tif extension: > r.mapcalc "warm.tif = if(modis_celsius > 20.0, modis_celsius, null() )" > > # cease GDAL output connection and turn back to write standard GRASS > raster files: > r.external.out -r > > # use the result elsewhere > qgis $HOME/gisoutput/warm.tif > > Best > Markus > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user >
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