[geos-devel] [GEOS] #588: valid polygon when cw, not valid when ccw
GEOS
geos-trac at osgeo.org
Wed Sep 12 03:14:56 PDT 2012
#588: valid polygon when cw, not valid when ccw
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Reporter: olivier80 | Owner: geos-devel@…
Type: defect | Status: new
Priority: major | Milestone: 3.3.6
Component: Default | Version: 3.3.5
Severity: Unassigned | Keywords:
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Comment(by strk):
The polygon ring has 7 points, but it's a 4 sides polygon. So 2 vertices
are very close to other vertices.
I'd love to have a function (in postgis) to analyze these cases and answer
questions like: what's the minimum distance between two consecutive
vertices ? what's the minimum distance between any two vertices ?
Simplifying the geometry with a tolerance of 1e-10 is enough to fix the
invalidity, but anyway the robustness problem exists. I didn't try with
JTS but I suspect it may be an issue there as well.
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Ticket URL: <http://trac.osgeo.org/geos/ticket/588#comment:3>
GEOS <http://geos.refractions.net/>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).
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