[geos-devel] Re: [GEOS] #527: Union and UnaryUnion both fail at correctly node input lines

[GEOS]

#527: Union and UnaryUnion both fail at correctly node input lines
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 Reporter:  strk        |       Owner:  geos-devel@…              
     Type:  defect      |      Status:  new                       
 Priority:  major       |   Milestone:  3.3.4                     
Component:  Default     |     Version:  3.3.3                     
 Severity:  Unassigned  |    Keywords:                            
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Comment(by strk):

 Uff, ST_IsSimple isn't a good check when it comes to _closed_ lines, in
 that they have no bounday so the node would be considered as an
 interior/interior intersection, like here:

 MULTILINESTRING((0 0, 10 0, 10 10, 0 0), (0 0, -10 0, -10 -10, 0 0))

 The boundary node rule is really getting in my way.

 @mbdavis : how can I check for correct noding ? And is Polygonizer happy
 with noding which involves closed lines ?

 /me goes on to try again the polygonizer call with more closed lines.

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Ticket URL: <http://trac.osgeo.org/geos/ticket/527#comment:1>
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GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).