[postgis-devel] [PostGIS] #399: ST_CleanGeometry

PostGIS trac at osgeo.org
Sun Feb 21 14:15:22 PST 2010


#399: ST_CleanGeometry
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  Reporter:  strk     |       Owner:  strk         
      Type:  task     |      Status:  assigned     
  Priority:  medium   |   Milestone:  PostGIS 2.0.0
 Component:  postgis  |     Version:               
Resolution:           |    Keywords:               
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Comment (by strk):

 So, as of r5281 the ST_MakeValid function does a good job at retaining all
 input vertices. It does so at the cost of putting some lines in a
 collection
 togheter with polygons. But also, it tries its best to reduce the amount
 of
 lines stuffed in by dropping those that have all vertices already
 represented
 as nodes on the areal part boundary.

 You still get lines which fall *inside* the areal part, if they do have
 vertices
 which are not on the boundary.

 Now I guess a ST_GeometryClean might try to do something with those lines.
 For example, if tolerated (how to express?) it could just drop those
 collapsed
 portions of rings. Or it could try to make a very small buffer on them.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/399#comment:25>
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