On Fri, May 14, 2010 at 11:35:45AM -0700, Martin Davis wrote: > Ok, I tried the roads_broken geometry in JTS using the buffer-and-union > approach. The result matches the one you posted, strk. > > Time was 2.7 s. So the two systems are pretty close. > > It would be interesting if you tried the other geometry as well.
Done, but on another (older) machine: Intel(R) Pentium(R) 4 CPU 2.66GHz bogomips : 5333.43 Input points: 11502 Input components: 5615 Output points: 417 $ time psql -c ' select st_npoints(st_union(st_buffer(geom, 0.005))) from ( select (st_dump(g)).geom from bug ) as foo; ' real 1m9.838s user 0m0.100s sys 0m0.028s Memory is fine, CPU is pretty much fixed at 100%. Interesting enough the buffer itself is pretty quick: $ time psql -c ' select sum(st_npoints(st_buffer(geom, 0.005))) from ( select (st_dump(g)).geom from bug ) as foo;' real 0m3.170s user 0m0.108s sys 0m0.024s --strk; () Free GIS & Flash consultant/developer /\ http://strk.keybit.net/services.html _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/geos-devel