A possible explanation could be that QGIS doesn't pick up the correct ellipsoid definition from the CRS metadata. I had a hunch that might be the problem but couldn’t come up with a test to confirm it. I suspect it would be simple to test in debug mode.
/Kristian -----Oprindelig meddelelse----- Fra: QGIS-Developer <qgis-developer-boun...@lists.osgeo.org> På vegne af Nyall Dawson Sendt: 27. september 2018 08:32 Til: hel...@web.de Cc: qgis-developer <qgis-developer@lists.osgeo.org> Emne: Re: [QGIS-Developer] [Qgis-user] New Features in Shape Tools 3.2.0 On Wed, 26 Sep 2018 at 03:52, Helmut Kudrnovsky <hel...@web.de> wrote: > > >[...] > >Caris LOTS: 14.737 km^2 > >ArcMap: 14.727,446 km^2 > >MapInfo: 14.727,352 km^2 > >GeoMedia: 14.726,443 km^2 > >Planimeter: 14.722,522 km^2 > >QGIS 3.2: 14.652,181 km^2 > >QGIS 2.8: 14.652,181 km^2 > >[...] > >My suspicion is that the geodesic algorithm used by QGIS (and apparently > GRASS) is to blame here. > > a quick check in GRASS 7.7.svn shows :-) > > |m2|km2| > |14718097678,673|14.718,097679| Hmm... confusing. I've double checked and the QGIS/GRASS code matches, so we should get identical results. The cause must lie in the data passed to the area calculation. I'll investigate. Nyall _______________________________________________ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer _______________________________________________ QGIS-Developer mailing list QGIS-Developer@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
