Hi An update on my message from earlier this morning :
since Shapely is not showing the details of the TopologicalError message, I decided to write a small C++ program to run the difference operation in GEOS directly. See new attachment attached (I include the C++ code, the Python script and the WKT files). I now get this message : TopologyException: found non-noded intersection between LINESTRING (1.96875 -1.225, 1.89 -1.225) and LINESTRING (1.96875 -1.225, 1.89 -1.225) at 1.96875 -1.225 I have 2 questions : 1) How can I manipulate the two polygons so that I can run the difference operation ? 2) Why are the details of the TopologicalError message not shown in Python? Is this a point where shapely can be improved, or is there a technical restriction? wbr Emmanuel On Tue, 2011-02-22 at 09:26 +0100, Emmanuel Lambert wrote: > Hi, > > Attached is a python script and 2 AWT-files with a polygon and > multipolygon. > > The python script reproduces the following problem : > > p1.difference(p2) : shapely.geos.TopologicalError: This operation > produced a null geometry. Reason: unknown > > I cannot see what causes this TopologicalError. A small change in our > geometry makes this operation working fine again. > > Both polygons look perfectly correct. Can somebody with a more in-depth > expertise in Shapely and GEOS take a look at this please? > > many thanks, > > Emmanuel > > > > _______________________________________________ > Community mailing list > [email protected] > http://lists.gispython.org/mailman/listinfo/community
topologicalerrorv2.tar.gz
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