[geos-devel] Update to 3.9?

[Martin Davis]

Actually OverlayNGRobust.unaryUnion will compare the current OverlayNG code
to GEOS. However, OverlayNG is likely to be slower, in any case.

So:
GEOS - 6.1 s
JTS 14.4 s

That's an impressive difference in favour of GEOS.  I wonder why Paul's
timings are so different?

On Wed, Nov 25, 2020 at 6:00 PM Daniel Baston <dbaston at gmail.com> wrote:

> After collecting the inputs and writing to WKT:
>
> \copy (select st_astext(st_collect(geom), 18) from wsa_vi) to
> ~/data/wsa.wkt;
>
> I'm seeing 6 seconds in GEOS (not including WKT parsing)
>
> bin/perf_unary ~/data/wsa.wkt union
> # Reading geometries from /home/dan/data/wsa.wkt
> # Read 1 geometries.
> # 6,137,885 usec
>
> vs 14s in JTS (including WKT parsing)
>
> time bin/jtsop.sh -a ~/data/wsa.wkt -op Overlay.unaryUnion
> # 14.43s user 0.47s system 202% cpu 7.354 total
>
> Dan
>
>
>
> On Wed, Nov 25, 2020 at 8:21 PM Paul Ramsey <pramsey at cleverelephant.ca>
> wrote:
>
>>
>>
>> > On Nov 24, 2020, at 5:01 PM, Regina Obe <lr at pcorp.us> wrote:
>> >
>> >
>> >> All the performance talk is mostly because JTS still runs a lot faster
>> > than GEOS
>> >> for some bulk processing. My current test is a big union of watershed
>> >> boundaries, about 6MB of data, which takes about 20s under GEOS and
>> >> about 25% of that under JTS.  It's a big gap, and in theory the two
>> code
>> > bases
>> >> are pretty aligned right now. Same overlayNG engine, etc. So I figure
>> > there
>> >> has to be a big implementation ball of performance hiding under the
>> covers
>> >> somewhere. No luck thus far.
>> >>
>> >> I think we're close, looking forward to release :)
>> >>
>> >> P
>> >> _______________________________________________
>> >> geos-devel mailing list
>> >> geos-devel at lists.osgeo.org
>> >> https://lists.osgeo.org/mailman/listinfo/geos-devel
>> >
>> > You have your sample watershed data set.  Would like to test it out
>> myself.
>>
>> https://www.dropbox.com/s/9ruvs6gxe3yl93c/wsa_vi.sql.bz2?dl=0
>>
>> I union all these. It takes about 20s on my Air.
>>
>> p
>>
>> >
>> > Thanks,
>> > Regina
>> >
>> > _______________________________________________
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>> > geos-devel at lists.osgeo.org
>> > https://lists.osgeo.org/mailman/listinfo/geos-devel
>>
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