[geos-devel] Port of PostGIS ST_Subdivide to GEOS / downstream libraries

[Brendan Ward]

I would like to expose functionality similar to ST_Subdivide (
https://postgis.net/docs/ST_Subdivide.html) in pygeos (ref:
https://github.com/pygeos/pygeos/issues/244), which provides a Python
interface to GEOS.

The algorithm recursively subdivides input geometries along alternating x
vs y dimensions until a target number of vertices per geometry is
reached, which can greatly improve spatial index performance for complex
polygons (e.g., countries with coastlines).  Paul has written a very nice
overview of it here: http://blog.cleverelephant.ca/2019/11/subdivide.html

Apologies if this has already been raised here; I was unable to find any
record of such a discussion in Github, Trac, mailing list archives.

I did not find a counterpart in JTS, so perhaps this is out of scope for
GEOS?

While we can take this on in a downstream library (and indeed may want to
pilot there first), this seems like it would have broader appeal to the
GEOS community if exposed via the C API.  There may also be potential
performance improvements to leveraging aspects of something like STRtree to
help identify x or y subdivision points (ideas not yet well developed
though).

Is there any interest in providing something similar within GEOS?  If so,
perhaps the next stage is to log this as a feature request to Trac.  I
anticipated the need for a little discussion around this topic, so I'm
raising here first.

Thanks,

BCW

-- 
Brendan C. Ward
Owner | Lead Software Engineer
Astute Spruce, LLC
astutespruce.com
541-250-9544
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