[postgis-users] Split multiple overlapping polygons to polygons that do not overlap.

[Dylan Beaudette]

On Thursday 22 October 2009, Moen, Paul T. wrote:
> I have a set of polygons.
>
> INSERT INTO test(gid,the_geom) VALUES (1,st_geomfromtext('MULTIPOLYGON
> (((1 5,1 9,5 9,5 5,1 5)))',2266));
> INSERT INTO test(gid,the_geom) VALUES (2,st_geomfromtext('MULTIPOLYGON
> (((4 2,4 6,8 6,8 2,4 2)))',2266));
> INSERT INTO test(gid,the_geom) VALUES (3,st_geomfromtext('MULTIPOLYGON
> (((4 3,4 6,7 6,7 3,4 3)))',2266));
> INSERT INTO test(gid,the_geom) VALUES (4,st_geomfromtext('MULTIPOLYGON
> (((4 5,4 8,7 8,7 5,4 5)))',2266));
> INSERT INTO test(gid,the_geom) VALUES (5,st_geomfromtext('MULTIPOLYGON
> (((2 3,2 6,5 6,5 3,2 3)))',2266));
> They look like the image below with the transparency set so the
> overlaps are visible.

Hi,

This would be a simple import/export operation in GRASS, due to the 
topologically-aware storage format that it uses.

Cheers,
Dylan

-- 
Dylan Beaudette
Soil Resource Laboratory
http://casoilresource.lawr.ucdavis.edu/
University of California at Davis
530.754.7341