Hello, I am trying to use the r.watershed function to calculate streams (rivers) from elevation data. As long as I make sure that the GRASS region is not too big things work fine, but in the end I would like to do the calculations at the resolution of the elevation data.
Let me first clarify what I mean with big in this case. I can do the calculations with regions up to 10000x10000 pixels, but above that I start to run into trouble. My elevation data is about 80000x60000, so I guess that is quite big. So my first question would be: Is the file I try to process too big or has r.watershed been run successfully on such big files? >From the mailing list I understand GRASS needs to be compiled with large file support to work with such big files. I am not sure if my version is, I have tried in on Windows with the stable version 6.4 from the OSGeo4W installer and on Ubuntu with the 6.4 version from their repository. This is the error I got on Ubuntu while running r.watershed: SECTION 3 beginning: Initiating Variables. 5 sections total. WARNING: No such file or directory WARNING: cseg_open(): could not write segment file Floating point exception WARNING: Subprocess failed with exit code 34817 Any advice on how to prevent this error? Thanks, Arno _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
