Maxime, ST_AsText does not produce the fidelity of the geometry. It truncates floating points and I think where they truncate between GEOS and PostGIS is different. GEOS and PostGIS do not share the same WKT writers.
My question is -- have you tried validating the WKB in GEOS. The WKB should maintain fidelity so you should get the same IsValid answer in both those cases. Leo -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Maxime van Noppen Sent: Saturday, July 11, 2009 8:35 AM To: PostGIS Users Discussion Subject: [postgis-users] WKT differs in PostGIS and Geos Hello, I've got a strange issue. When I print a polygon from PostGIS (v1.3.6) thanks to the AsText() function I get a different result than if I read the WKB into a geos (v3.1.0 and v3.1.1) geometry object and than write it with geos::io::WKTWriter. When asking PostGIS to check the geometry's validity (via ST_IsValid) it says it is valid whereas Geos says it isn't (via the geos::geom::Geometry::isValid function). I've attached a text file containing the WKB geometry as it appears in the database, the WKT given by AsText and the WKT given by geos. Thank you for your help ! -- Maxime _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
