Marcello Gorini wrote: > I have to find the maximum value for each cell in a series of rasters and > generate both a maximum value map and a categorical map with the raster > number which contains the maximum value. > > R.series is, therefore, perfect to accomplish that using > method=maximum,max_raster. > > My problem is that I also need to find the *second largest* value and the > corresponding raster number which contains the second largest value. > > I am doing that by iterating over all classes through a shell script, but it > obviously takes much more time than using a simple r.series command. > > Can anyone share any idea on how to accomplish that using r.series or > something similar?
There isn't an efficient way to do this using existing tools. If you need the efficiency, I suggest adding a "second largest" aggregate to lib/stats (based upon c_max.c and c_maxx.c), and updating r.series to use it. -- Glynn Clements <gl...@gclements.plus.com> _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user
