[geos-devel] [GEOS] #841: Regression in prepared polygons contains

[GEOS]

#841: Regression in prepared polygons contains
------------------------+-------------------------------
 Reporter:  sgillies    |      Owner:  geos-devel@…
     Type:  defect      |     Status:  new
 Priority:  major       |  Milestone:  3.6.3
Component:  Default     |    Version:  3.6.2
 Severity:  Unassigned  |   Keywords:  prepared contains
------------------------+-------------------------------
 Shapely users have found a regression in the contains predicate of a
 prepared polygon: https://github.com/Toblerity/Shapely/issues/519

 With GEOS 3.4.2 we see the following:


 {{{
 >>> from shapely.geometry import Point, Polygon
 >>> import shapely.prepared
 >>> point = Point(0.95, 0.05)
 >>> geom = Polygon([(0, 0), (1, 0), (0, 1), (0, 0)])
 >>> shapely.geos.geos_version
 (3, 4, 2)
 >>> shapely.prepared.prep(geom).contains(point)
 True
 >>> geom.contains(point)
 True
 }}}

 With GEOS version 3.5.1 and newer we observe

 {{{
 >>> shapely.prepared.prep(geom).contains(point)
 False
 >>> geom.contains(point)
 True
 }}}

--
Ticket URL: <https://trac.osgeo.org/geos/ticket/841>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).