On Donnerstag, 20. November 2008 13:57:42 Hufkens Koen wrote: > Hi list, > > I've got two maps, a map with patches or areas which I want to evaluate. A > second map contains a parameter which I want to evaluate (average, std) > based upon areas as delineated in the first map. The output of all this > would optimally be a third map with the results of the evaluation (average, > std) given to the areas of the first map. > > Is this possible in a simple way, or should I write something myself. I > can't seem to find a premade function that does this or something close to > it.
it is quit simple: 1) change your 'patch map' with r.to.vect and v.to.rast into individually numbered patches 2) change your value_raster to integer and multiplication (e.g. '*100') is advisable: r.mapcalc "tmp1=int(value_raster*100)" 3) query your raster: r.statistics base=patch_raster cover=tmp1 method=average out=value_raster --o 4) perhaps use r.mapcalc to revert the *100 modification in the new map regards, Martin -- ********************************************************************** University of Wuerzburg Institute of Geography Department of Remote Sensing Remote Sensing and Biodiversity Unit Am Hubland 97074 Wuerzburg, Germany @ German Aerospace Center (DLR) German Remote Sensing Data Center (DFD) Phone: +49-(0)931-888-4797 Fax: +49-(0)931-888-4961 Email: [EMAIL PROTECTED] url: http://www.remote-sensing.uni-wuerzburg.de ********************************************************************** _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
