[geos-devel] improvement of point/line intersection

[Sandro Santilli]

Thanks for the contribution Remi, but I wouldn't accept a change
that would make such a tolerance implicit. Not at that low level.

If the tolerance value is configurable via a parameter that'd
be fine. Note that a parameter should already exist in form
of a "precision model", but I haven't looked at the details
of neither the current GEOS code nor your patch yet.

--strk;

On Fri, Nov 22, 2013 at 05:25:00PM +0100, Rémi Cura wrote:
> Hey dear list,
> 
> after much worries,
> I just submitted a pull request to propose a very tiny change in geos
> LineIntersector.cpp file.
> 
> Now a point is considered to be on a line much more often, as line have a
> controlled thickness.
> 
> The thickness of a line is defined so that a point that shall be on the
> line with the correct first 12 digits would be on it, even if the other
> digits are wrong.
> 
> All lines have not the same thickness is real world units, because the
> tickness depends of the number of digits in coordinates.
> 
> 
> This improves a lot of function working with points and lines, and
> shouldn't change computation time (there where already 2 tests).
> 
> 
> With synthetic data precise to the millimeter across all France, I had no
> error for 1 million lines.
> Theoretically there could still be some lines that have no points. (one in
> 10 million or so?)
> I can't solve this without changing much more the current RobustDet
> algorithm.
> 
> 
> Cheers,
> 
> 
> Rémi-C