Dylan,
Yes! Clean polygons! I gravitated towards PostGIS due to my large number of
polygons (1.2 million), and I'd like a solution that is scalable beyond that
number. GRASS may be the/an answer; I'll give it a try.
Thanks!
Brent
Dylan Beaudette wrote:
On Wednesday 16 July 2008, Brent Fraser wrote:
Regina,
I'm not convinced ST_Union is the way to go (using ST_Overlaps OR
ST_Intersects as a condition). Basically I want to iterate over the
collection (recursively?) clipping one polygon to another until I'm left
with no overlapping (or intersecting) polygons (planar topology). This is
sightly more complicated than the way I originally posed the problem (I
wanted to created slivers from the overlapping areas to get planar
topology).
A little background:
My polygons represent a classification of vegetation of a large area of
interest. In theory any point in the area of interest must fall in one and
only one polygon. Due to an artifact of my image segmentation process, my
polygons currently have slight overlap which I need to "dissolve" (and I
don't care which polygon the overlap sliver gets dissolved into).
Thanks!
Brent.
It really sounds like you need to perform some "cleaning" operations in a
topologically-aware GIS. Check out the v.clean module in GRASS.
Cheers,
Dylan
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