[postgis-devel] [PostGIS] #845: ST_Intersects() precision error - returns false instead of true
PostGIS
trac at osgeo.org
Thu Feb 24 03:40:39 PST 2011
#845: ST_Intersects() precision error - returns false instead of true
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Reporter: cdestigter | Owner: pramsey
Type: defect | Status: new
Priority: medium | Milestone: PostGIS 2.0.0
Component: postgis | Version: 1.5.X
Keywords: |
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Comment(by nicklas):
No, It's not.
In distance functions the pt_in_ring function is used for point in polygon
tests. I guess that is why ST_Distance returns 0.0. pt_in_ring is a stab-
line algorithm implementation that is old. So we also have a winding
number algorithm implementation.
Is there a reason to have two different? I have read somewhere that the
winding number algorithm is more stable (when bugs are fixed) and the same
performance.
In 3D I have rewritten pt_in_ring to project the polygon to 2D and then
use stabline algorithm. Maybe it is time top clean up and get winding
algorithm working and move to that also in distance?
What is the name on that function?
/Nicklas
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Ticket URL: <http://trac.osgeo.org/postgis/ticket/845#comment:5>
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