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Subject: [ggl] distance and convex hull for multi-geometries
From: Mateusz Loskot (mateusz)
Date: 2009-04-30 18:46:09

Barend Gehrels wrote:
> Hi,
> I implemented the distance algorithm for multi geometries
> (single-to-multi, multi-to-multi).


> This is to verify this discussion:
> (I need it next week in BoostCon).
> Distance is not yet completed but these ~100 lines of code cover 75% of
> the matrix of 36 possibilities (6x6, point-point, point-linestring, etc)...
> Future improvement: they would probably profit from a spatial index on
> multi-s.

Wow! That's a nice number of possibilities :-)

> Furthermore I also implemented convex hull for multi-points (email
> Nicolas) and multi-linestrings/multi-polygons.
> I therefore also created a tiny utility "as_range" which can see the
> exterior ring of a polygon as a range. Having as_range, polygons don't
> have to be handled differently.

Nice idea.

Unfortunately, I don't have time to test it at this moment,
but will try to do it in near future.

Best regards

Mateusz Loskot,
Charter Member of OSGeo,

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