[CC'd to grass-dev.] beakins wrote:
> One question that I have: "Is there another file format for the ETOPO1 grids > that would be of more use to the GRASS community than netcdf?" We could host > something such as geotiffs of the grids, which we can create easily, but I'm > not a GRASS user so don't know what grid/raster file format would be easiest > to import into GRASS. I've also never used QGIS. > > Any ideas or suggestions would be much appreciated. GRASS' preferred raster format is anything which GDAL supports, and for which GetGeoTransform() succeeds, with the adfTransform[] array satisfying the constraints: adfTransform[1] > 0 adfTransform[2] == 0 adfTransform[4] == 0 adfTransform[5] < 0 [Currently, r.in.gdal/r.external don't bother to check adfTransform[1]; if it's negative, GRASS may import it okay, but then refuse to read it.] IOW, north-to-south, west-to-east, no rotation or shear. If the data uses a different orientation, GDAL needs to be able to transform it itself. It isn't a major problem if the georeferencing data isn't readily available, but a different orientation is (at present). Ultimately, we could make some changes to support flipped (but not rotated) rasters, but the format would ideally need to be such that there isn't a penalty for reading data north-to-south, i.e. any south-to-north data would need to be in a format which supports non-sequential access (seeking). -- Glynn Clements <[EMAIL PROTECTED]> _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user