On Fri, 18 Feb 2022 at 08:08, Bernd Vogelgesang <bernd.vogelges...@gmx.de> wrote: > > Hi Sebastian, > > thanx, that worked. > > But somehow, the hole process feels a bit clumsy. > > Having to fumble together a classification with "thru" (juck!), then the > toolbox reclassify just seems to be broken,
Which reclassify tool are you referring to exactly? The native QGIS ones are 100% NOT broken. (The SAGA one may be, but that's a 3rd party tool.) Nyall gladly gdal calculator does ... > > Why isn't there some "raster SQL" that saves one from all these stupid single > steps? > > Ok, will then try to build a model and hope it will work for the tests to > come… > > Thanks a lot, > > Bernd > > > Am 17.02.22 um 22:19 schrieb Sebastian Gutwein: > > Reclassify your Layer 1 to be anything greater than 1 = 0 everything else > equals 1. This will give you a binary 1 and 0 raster (Layer 3) that you can > use in the raster calculator: Layer 2 * Layer 3. Anywhere where layer 3 is 1 > your layer 2 values will stay the same and anywhere where layer 3 is 0 your > layer 2 values will become 0. > > On Thu, Feb 17, 2022 at 3:19 PM Bernd Vogelgesang <bernd.vogelges...@gmx.de> > wrote: >> >> Hi folk, >> >> I hardly never work with raster calculations, and unfortunately there is >> nowhere a collection of syntax examples for different use cases to be found >> (documentation :( ). >> >> Anything apart from +-*/ is beyond my scope. >> >> So, >> >> I made a viewshed analysis over a digital surface model (try the awesome >> Visibility Analysis plugin form Zoran Čučković and buy him a beer!) >> >> A lot of "views" are caught by tree canopy, but I am only interest in the >> flat grounds. >> >> So I substracted the surface model layer from the ground model layer, and >> this is Layer 1. >> >> Giving a threshold of 1 meters difference for inaccuracities, all pixels in >> this layer above 1 should result in 0 (zero) in my viewshed raster (Layer 2) >> >> Please give me some hints, >> >> Cheers, >> >> Bernd >> >> >> _______________________________________________ >> Qgis-user mailing list >> Qgis-user@lists.osgeo.org >> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user >> Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user > > _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user _______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
