On Wed, May 2, 2018 at 7:13 PM, Martin Landa <[email protected]> wrote: > Hi, > > one of my colleague is dealing with flow accumulation calculation in > GRASS, and comparing results with Esri ArcGIS (builtin Flow > Accumulation [1]). Tool in ArcGIS to me knowledge uses D8, so we run > r.watershed with -s flag and also -a flag to avoid negative values. > Resultant values are very different. > > * Esri ArcGIS (range: 0 - 20741) > * r.watershed -s (range: -34068 - 5697) > * r.watershed -sa (1 - 34068)
I'd suggest to look at the univariate statistics first (r.univar -e) and compare that instead of min/max only. markusN > Do you have idea why results are so different? Thanks for any pointers > in advance! Martin > > [1] > http://desktop.arcgis.com/en/arcmap/10.5/tools/spatial-analyst-toolbox/flow-accumulation.htm > > -- > Martin Landa > http://geo.fsv.cvut.cz/gwiki/Landa > http://gismentors.cz/mentors/landa > _______________________________________________ > grass-user mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-user -- Markus Neteler, PhD http://www.mundialis.de - free data with free software http://grass.osgeo.org http://courses.neteler.org/blog _______________________________________________ grass-user mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-user
