[geos-devel] strange behaviour of LinearRing::within()

Marco Hugentobler marco.hugentobler at karto.baug.ethz.ch
Wed Jun 13 05:25:56 EDT 2007

On Tuesday 12 June 2007 23:14:11 Martin Davis wrote:
> Marco,
> I suspect this is because you are expecting linear rings to "contains"
> the area they enclose. But this is not how linear rings are defined -
> they are 1-dimensional features, not areal ones.  A linear ring would
> only be "within" another one if its linework lay exactly on top of the
> other one's linework.   GEOS is behaving correctly, according to the SFS
> geometry model.

Hi Martin,

Ok, I see. Thanks for clarification.


Dr. Marco Hugentobler
Institute of Cartography
ETH Zurich
marco.hugentobler at karto.baug.ethz.ch

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