Martin Wegmann wrote: > Hello, > > I am looking for a function related to "curve sketching" > (Kurvendiskussion in german) - I think r.series would be the perfect > place for it, but before submitting a wish, I just wanted to ask if > there already exists a module which fullfills this task. > > If would be very handy to have functions like: > > - point of global maximum (already in r.series -> max_raster) > - point of global minimum (already in r.series -> min_raster) > - turning point (Wendepunkt) > - point of max./min. slope (e.g. growing season, senescence) > - information about unimodal/bimodal etc. phenology (no idea how to > add this) > > Some functions are listed on the german Wikipedia (1) - the eng. > pendant is not as elaborated (2) .. > (1) http://de.wikipedia.org/wiki/Kurvendiskussion > (2) http://en.wikipedia.org/wiki/Curve_sketching
Here's a way: eval `r.univar -g elevation.dem | grep ^max=` r.mapcalc maxelev="if(elevation.dem == $max, elevation.dem, null())" r.out.xyz maxelev # in GRASS 6.2 use "r.stats -1gn" (may get multiple points with the same elev) see also r.param.scale param=feature (and other param opts) and r.slope.aspect I have wondered how to impelement topographic prominence for a DEM: http://en.wikipedia.org/wiki/Topographic_prominence http://en.wikipedia.org/wiki/List_of_mountains_by_prominence Hamish _______________________________________________ grassuser mailing list [email protected] http://grass.itc.it/mailman/listinfo/grassuser
