Bug report #390
GEOS: TopologyException occuring with identify tool
Status: | Closed | ||
---|---|---|---|
Priority: | Low | ||
Assignee: | Gary Sherman | ||
Category: | Vectors | ||
Affected QGIS version: | Regression?: | No | |
Operating System: | All | Easy fix?: | No |
Pull Request or Patch supplied: | Resolution: | fixed | |
Crashes QGIS or corrupts data: | Copied to github as #: | 10449 |
Description
Hi,
via IRC I reported this problem and "wonder" fixed something already:
http://svn.qgis.org/trac/changeset/6071
I have now recompiled QGIS and latest 2.x GEOS. The identification now seems to work,
but still these warnings appear:
Warning: GEOS: [[TopologyException]]: side location conflict (4.33168e+06,2.52514e+06) Warning: GEOS: [[TopologyException]]: side location conflict (4.34597e+06,2.51173e+06) Warning: GEOS: [[TopologyException]]: side location conflict (4.39699e+06,2.59723e+06)
The sample SHAPE file is here: http://mpa.itc.it/markus/tmp/qgis/
It comes with some huge multipolygons.
I also contacted strk who told me (pasted with permission):
strk*refractions.net wrote on 11.11.2006 11:32: > The topology exceptions are not considered real bug, but rather > a limit of the algorithms. New algorithms in GEOS-3.0.0 > use some heuristics on exception and try to reapply the operation > on a sligtly modified input to reduce likelyness of robustness issues. > > I think qgis should be using the C-API, where all of this comes for > free (and GEOS-2.2.x should have the C-API already, so qgis will be > binary compatible back to that version of geos). Alternatively you > can probably still using the C++ api and make it compatible with both > 2.2.x and 3.0.0 geos by adding some 'using namespace' directives IFF > major_version > 2. > > --strk;
Best regards,
Markus
History
#1 Updated by Marco Hugentobler about 17 years ago
- Resolution set to fixed
- Status changed from Open to Closed
I'm closing this ticket as it is possible to compile and link qgis against geos 3 (with -DPEDANTIC=off)
#2 Updated by Anonymous about 15 years ago
Milestone Version 0.9 deleted