[Jts-topo-suite-user] Geomtry errors Was RE: ound non-noded intersection between LINESTRING ( 2151080.185900285 5143376.314099715, 2151080.185900287 5143376.314099713 ) and LINESTRING ( 2151080.185900285 5143376.314099715, 2151080.2 5143376.3 ) [ (2151080.185900285, 5143376

[Dave P. <dav...@pi...>]

Hi List,

I having some real issues at the moment with union, intersection and
diffrences between geometries.

I am working in srs 3857, the google projection.

I have had some issues with with non-noded intersection between LINESTRING
 etc problems.  I have done things like applying a  PrecisionModel(3) and
doing buffer(0) on Geometry when I have been calculating an intersection
or union etc.  This seems to ensured that  non-noded intersection problems
disappear.

I now get issues intersections.  If I attempt to answer the question is
this POINT geometry in side this  polygon geometry I tend to get an empty
GometryCollection object returned with an area of zero. Looking at the
polygon and point geometries  with qgis,  I can see that the point is in
side the polygon, so I do not understand when intersection routine is
returing such a result

Any suggestions??  and what does the empty Geometrycollection object with
an area of 0.0 actually mean???


Dave.
Dave Potts wrote:
> Hi David,
>
> I tried the following
>
> final PrecisionModel pmFixed3 = new PrecisionModel(3);
> ret=SimpleGeometryPrecisionReducer.reduce(ret, pmFixed3);
>
> It seems to have solved that  problem,  I now have to deal with a
> unexpected  GeometryCollection else where :-(
>
> Dave.
>
>
>
> David Zwiers wrote:
>> Hi Dave,
>>
>> I've run into similar issues using double precision. Typically my
>> approach has been to round the ordinates by applying a PrecisionModel
>> before performing any geometric operations. You'll want to pick a
>> precision value that is appropriate for your dataset; based on your
>> error points I'm guessing 1:1000 (milli-meter) would be more than
>> enough.
>>
>> David
>>
>>
>> -----Original Message-----
>> From: Dave Potts [mailto:dav...@pi...]
>> Sent: Monday, August 27, 2012 3:34 PM
>> To: jts...@li...
>> Subject: [Jts-topo-suite-user] ound non-noded intersection between
>> LINESTRING ( 2151080.185900285 5143376.314099715, 2151080.185900287
>> 5143376.314099713 ) and LINESTRING ( 2151080.185900285
>> 5143376.314099715, 2151080.2 5143376.3 ) [ (2151080.185900285,
>> 5143376.314
>>
>>
>> Hi List,
>>
>> I am trying to do a union of two polygons and get the following error
>>
>> Processing Rome
>> com.vividsolutions.jts.geom.TopologyException: found non-noded
>> intersection between LINESTRING ( 2151080.185900285 5143376.314099715,
>> 2151080.185900287 5143376.314099713 ) and LINESTRING ( 2151080.185900285
>> 5143376.314099715, 2151080.2 5143376.3 ) [ (2151080.185900285,
>> 5143376.314099715, NaN) ]
>> 	at
>> com.vividsolutions.jts.noding.FastNodingValidator.checkValid(FastNodingV
>> alidator.java:109)
>> 	at
>> com.vividsolutions.jts.geomgraph.EdgeNodingValidator.checkValid(EdgeNodi
>> ngValidator.java:94)
>> 	at
>> com.vividsolutions.jts.geomgraph.EdgeNodingValidator.checkValid(EdgeNodi
>> ngValidator.java:59)
>> 	at
>> com.vividsolutions.jts.operation.overlay.OverlayOp.computeOverlay(Overla
>> yOp.java:170)
>> 	at
>> com.vividsolutions.jts.operation.overlay.OverlayOp.getResultGeometry(Ove
>> rlayOp.java:127)
>> 	at
>> com.vividsolutions.jts.operation.overlay.OverlayOp.overlayOp(OverlayOp.j
>> ava:66)
>> 	at
>> com.vividsolutions.jts.operation.overlay.snap.SnapOverlayOp.getResultGeo
>> metry(SnapOverlayOp.java:67)
>> 	at
>> com.vividsolutions.jts.operation.overlay.snap.SnapOverlayOp.overlayOp(Sn
>> apOverlayOp.java:24)
>> 	at
>> com.vividsolutions.jts.operation.overlay.snap.SnapIfNeededOverlayOp.getR
>> esultGeometry(SnapIfNeededOverlayOp.java:76)
>> 	at
>> com.vividsolutions.jts.operation.overlay.snap.SnapIfNeededOverlayOp.over
>> layOp(SnapIfNeededOverlayOp.java:25)
>> 	at
>> com.vividsolutions.jts.geom.Geometry.union(Geometry.java:1198)
>> 	at EZone.engine.EZoneEngine.doGeomOp(EZoneEngine.java:1615)
>>
>> What does it mean, the supply polygons are valid, is there any easy way
>> round it?
>>
>> Dave
>>
>>
>>
>> --
>>
>>
>>
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>
>
> --
>
>


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