[postgis-devel] What is the meaning if this NOTICE?

[Sandro Santilli]

On Thu, Mar 22, 2012 at 01:32:34PM -0400, Pierre Racine wrote:
> > > Actually the message sent by the trunk looks more like this:
> > >
> > > ERROR:  GEOSDifference: TopologyException: found non-noded intersection
> > between LINESTRING (-1.11776e+06 848032, -1.11774e+06 848063) and
> > LINESTRING (-1.11774e+06 848063, -1.11776e+06 848032) at -
> > 1117759.3668995597 848039.56686744024
> > 
> > Different symptoms of the same cause: numerical robustness.
> 
> Is there anything I can do to get ST_Difference to work on those geometries? I tried ST_MakeValid(ST_CollectionExtract(geom, 3)) without success.

You can try ST_SnapToGrid with some 1e-10 value and grow from there if
it still fails.

--strk; 

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