And light was done! Objective: to get planimetric-UTM-my-zone areas, in square Km, from a LatLong layer, just at one step: in Fields calculator
area( transform( $geometry,'EPSG:4326', 'EPSG:32717' ))/1000000 Sorry, I was wrong for years, reprojecting layers; deactivating OTF SRC; and using $area function: It happens when you don't read help in front of you and don't try "new" functions. Carlos 2016-10-19 15:11 GMT-05:00 Carlos Cerdán <sig.up...@gmail.com>: > > > Under project properties, general tab - change "ellipsoid" to "None > /Planimetric". > > Done, but calculated area is still... geodetic area?. I've tried ArcGIS > and, for my GEO layer, It gives me desired area (same as an UTM layer, > calculated with OTF off); so, it's me or QGIS, but I can't do this task in > one step on QGIS: first I've to reproject mi GEO layer into an UTM one; > disable OTF and finally calculate area (planar, as UTM is) in the new UTM > layer. > > > Carlos🤔 > > > > > 2016-10-18 19:58 GMT-05:00 Nyall Dawson <nyall.daw...@gmail.com>: > >> On 19 October 2016 at 02:22, Carlos Cerdán <sig.up...@gmail.com> wrote: >> > It was my fault. I was used to consider plane areas as "correct", >> forgetting >> > ellipsoidal areas. So, QGIS give us freedom to calculate planar or >> > ellipsoidal (geodetical) areas, but we must be careful about settings; >> Is >> > not it?. Sometimes, too much freedom is annoying! >> > >> > But, How can I calculate UTM (planar) area from a GEO layer in one step? >> >> Under project properties, general tab - change "ellipsoid" to "None / >> Planimetric". >> >> I keep meaning to split up the concept of ellipsoidal measurement from >> OTF reprojection. In my view these are two different concepts - one is >> just about display of data, the other relates to measurement. Ie, you >> should be able to perform ellipsoidal calculations even if OTF >> rendering is disabled. >> >> I just keep forgetting to do it early in a release cycle for extensive >> testing... >> >> Nyall >> >> >> >
_______________________________________________ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: http://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-user
