[postgis-users] simplifying a polygon

Dave Potts dave.potts at pinan.co.uk
Fri Apr 6 14:52:17 PDT 2012


I have polygon made up of many different points,it some cases its rather
to accurate for my requirments,i.e. its generating a lot points to
describe a minor change.

I had throught that by saying something like


select ((st_dumppoints(
(st_intersection(ST_Segmentize(st_exteriorRing(jt.the_Geom),70000),pa.the_geom))
)).geom) as the_geom from
                 journey_table jt, coast_polygon  pa where  jt.generation=1

Would give me minmum list of data points for describing a polygon.  What
it does give me long gap, 3 coordinates, another long grap then another 3
coorindates etc

Where these 3 coordinates are they close together.  What I had hope to get
list the lowest number points that would be useful to describe a polygon.

Q.  Is there a better way of doing this.

Dave.





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