It's not a valid polygon,
SELECT st_isvalidreason(ST_GeomFromText('POLYGON((-1 -1, 2 2, 0 1, -1
-1),(3 3, 5 5, 3 5, 3 3))'));
st_isvalidreason
------------------------------
Hole lies outside shell[3 3]
(1 row)
So the answer is going to be unpredictable.
P.
On Fri, Aug 17, 2012 at 12:58 PM, george young <georgeryo...@gmail.com> wrote:
> PostgreSQL 9.1.4 on x86_64-unknown-linux-gnu, compiled by gcc (GCC)
> 4.4.4 20100630 (Red Hat 4.4.4-10), 64-bit
> postgis-2.0.1, libgeos_c.so.1.7.5
>
> gis=# SELECT st_area(ST_GeomFromText('POLYGON((-1 -1, 2 2, 0 1, -1
> -1),(3 3, 5 5, 3 5, 3 3))'));
> st_area
> ---------
> -0.5
>
> what does this mean? What is negative area?
> In general, what are the semantics of polygons with more than one
> sequence of vertexes?
> _______________________________________________
> postgis-users mailing list
> postgis-users@postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
_______________________________________________
postgis-users mailing list
postgis-users@postgis.refractions.net
http://postgis.refractions.net/mailman/listinfo/postgis-users
