Hey, this is partially true. It behaves strangely when you hit precision limits.
Cheers, Rémi-C 2013/10/18 Nicklas Avén <[email protected]> > If I understand you right your assumption is true. > > What makes you wondering? > > In 2d you will always get the distance to a vertexpoint in at least one > of the two geometries. > > You can use ST_ShortestLine to see between what points the distance is > calculated. > > So: > > SELECT ST_Distance('LINESTRING(1 1, 1 10)'::geometry, 'LINESTRING(2 5, > 10 5)'::geometry); > returns 1 > and > SELECT ST_AsText(ST_ShortestLine('LINESTRING(1 1, 1 10)'::geometry, > 'LINESTRING(2 5, 10 5)'::geometry)); > returns 'LINESTRING(1 5, 2 5)'::geometry > > geography type calculations is of course another story. > > > HTH > > Nicklas > > > > > 2013-10-18 Peter Hopfgartner wrote: > > I took it for granted, that ST_Distance between two two dimensional > >geometries followes the definition of > > > >dist(A, B) = inf(d(a,b)), where a is an arbitrary point in set A and b > >an arbitrary point in set B and d() is the euclidean distance > > > >For some reason I'm now wondering if my assumption is true. > > > >Thanks for your patience, > > > >Peter > > > >-- > >Peter Hopfgartner > >R3 GIS > > > >web : http://www.r3-gis.com > > > >_______________________________________________ > >postgis-users mailing list > >[email protected] > >http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users > > > > > > _______________________________________________ > postgis-users mailing list > [email protected] > http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users >
_______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
