[postgis-devel] Controlling GEOS PrecisionModel (was: TopologyException with geomunion)

strk at refractions.net strk at refractions.net
Wed Nov 9 03:42:35 PST 2005


[ included postgis-devel ]

On Wed, Nov 09, 2005 at 11:35:59AM +0000, David Orme wrote:
...
> Of course, I hadn't considered that I need to SnapToGrid the  
> geometries from the sequential unions rather than just the original  
> inputs so I'll try that.

This won't be easy, maybe we should add a function to control
precision of GEOS operations as a whole. Check out
lwgeom_geos_wrapper.cpp and try to change the PrecisionModel
constructor in initGEOS from the default to something like:

	PrecisionModel(0.00001);

This would teoretically *grid* every GEOS geometry
(input and output)

--strk;



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