[postgis-devel] When did ST_BuildArea change
Sandro Santilli
strk at kbt.io
Mon Oct 5 13:10:05 PDT 2020
Big problem. ST_Polygonize also affected:
strk=# select ST_AsTExt(ST_Polygonize('GEOMETRYCOLLECTION(POLYGON((0 0,10 0,10 10,0 10,0 0)),POLYGON((4 -2,6 -2,6 12,4 12,4 -2)))'::geometry));
st_astext
--------------------------------------------------------------------------------------------
GEOMETRYCOLLECTION(POLYGON((0 0,0 10,10 10,10 0,0 0)),POLYGON((4 -2,4
12,6 12,6 -2,4 -2)))
(1 row)
strk=# select ST_AsTExt(ST_BuildArea('GEOMETRYCOLLECTION(POLYGON((0 0,10 0,10 10,0 10,0 0)),POLYGON((4 -2,6 -2,6 12,4 12,4 -2)))'));
st_astext
--------------------------------------------------------------------------
POLYGON((0 0,0 10,4 10,4 12,6 12,6 10,10 10,10 0,6 0,6 -2,4 -2,4 0,0
0))
(1 row)
On Mon, Oct 05, 2020 at 03:21:16PM -0400, Regina Obe wrote:
> I noticed this before but came across it again.
>
>
>
> http://postgis.net/docs/manual-dev/ST_BuildArea.html
>
>
>
> At the time I created this page which I am guessing was like circa 2008
>
>
>
> This query created a gaping hole. Now it doesn't so the docs are wrong
>
>
>
> SELECT ST_BuildArea(ST_Collect(line,circle))
>
> FROM (SELECT
>
> ST_Buffer(
>
> ST_MakeLine(ST_MakePoint(10, 10),ST_MakePoint(190, 190)),
>
> 5) As line,
>
> ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50) As circle) As foo;
>
>
>
> --this creates the same gaping hole
>
> --but using linestrings instead of polygons
>
> SELECT ST_BuildArea(
>
> ST_Collect(ST_ExteriorRing(line),ST_ExteriorRing(circle))
>
> )
>
> FROM (SELECT ST_Buffer(
>
> ST_MakeLine(ST_MakePoint(10, 10),ST_MakePoint(190, 190))
>
> ,5) As line,
>
> ST_Buffer(ST_GeomFromText('POINT(100 90)'), 50) As circle) As foo;
>
>
>
> Docs say this:
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>
> But when I run in pgAdmin4 I get this:
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> Does anyone know when this behavior changed and why? I'm assuming it is a
> GEOS change, so cc'ing GEOS dev as well.
>
>
>
> More depressing is my signature symmetric podded Bee Hive on this page
> (circa 2010(
>
>
>
> http://postgis.net/docs/manual-dev/ST_LongestLine.html
>
>
>
> Which looked like this (minus the longest line of course) - beautiful isn't
> it?
>
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> Now looks like a shadow of its former self
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> Thanks,
>
> Regina
>
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