[Qgis-developer] Approximation and geoprocessing

Paolo Cavallini cavallini at faunalia.it
Mon Jan 13 09:00:11 PST 2014

Il 10/01/2014 15:18, Andreas Neumann ha scritto:

> But I can confirm that the whole analysis chain is a bit problematic
> with all these precision issues. As an example if you test intersections
> of buildings against parcels (2 different layers) and the building
> touches the parcel borders you may get very tiny intersects with parcels
> (only a few square cms) and you wouldn't want to include these
> intersections in your analysis.
> So it would be cool if for geometry tests there could be a notion of
> threshold values. If the area of an intersected polygon is below this
> value it wouldn't be taken into account during the analysis.
> These issues are really kind of show-stoppers and almost always require
> intermediate steps to sort out these edge cases. It would be very handy
> if the tools could handle this precision/uncertainty problems without
> having to do a lot of intermediate steps.

Agreed, this is a good approach IMHO.
Should I open a ticket?
All the best.

Paolo Cavallini - www.faunalia.eu
Corsi QGIS e PostGIS: http://www.faunalia.eu/training.html

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