[postgis-users] Coordinates and SRID - bound overflow, ST_Equals

Balint Persics persicsb at gmail.com
Thu Jan 20 03:30:47 PST 2011


Hi,

I have a very interesting problem, but I think some of you may have a
solution for that.

When I try to model Russia with EPSG:4326 coordinates, I "run out of
the bounds", e.g.  Russia's extent is so wide, it overlaps the
-180/+180 coordinate range of EPSG:4326, so the most
eastern part is in the western Hemisphere. When inserting points to
the geometry column, PostGIS allows me to insert both (186,45) and
(-174,45) (the former is out of the bounds of the reference, the
latter is okay). When I query the database whether these two points
are equal with ST_Equals, I get a false result , but in reality, they
are the same. I think there should be a version of ST_Equals which
compares the geometries taking into account their SRID.

Thanks,
Balint

-- 
Persics Balint



More information about the postgis-users mailing list