On Thu, Feb 23, 2012 at 07:13:12AM -0800, Martin Davis wrote: > I wonder about the PostGIS value, too. JTS gives 9.336164500133789.
Martin, JTS area calculator changed too recently (the shoelace formula). Could that explain ? BTW, here's what I get with PostGIS 2.0.0alpha7SVN: 9.33616450013379 --strk; ,------o-. | __/ | Delivering high quality PostGIS 2.0 ! | / 2.0 | http://strk.keybit.net - http://vizzuality.com `-o------' > On 2/23/2012 6:58 AM, Astrid Emde wrote: > >Hello, > > > >I calculate the area of polygons and get different results with diffrent > >programms. > > > >Here is an example polygon: > > > >Select st_area(geometryfromtext( > >'POLYGON (( > > 2569220.83 5630370.607, > > 2569215.357 5630374.968, > > 2569216.017 5630375.795, > > 2569216.19 5630376.01, > > 2569221.663 5630371.649, > > 2569220.83 5630370.607 > >))',31466) ); > > > >These are the results that I get: > >* PostGIS: 9.337890625 (with "POSTGIS="1.5.1" GEOS="3.2.0-CAPI-1.6.0") > > > >* AutoCAD Map 2012: 9.3362 > >* Kanal++ [1]: 9.3361645 > > > >PostGIS gives back a slightly bigger area than the other programms. Do you > > > >know why and who is right? > > > >Best regards > > > >Astrid > > > >[1] > >http://tandler.com/communal_gis/watermanagment/wastewater/sewer-gis-kanalplusplus.htm > > > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
