On Nov 9, 2009, at 7:43 PM, Helge Jensen wrote: > I am doing simplification of polygons for storage and calculation > efficiency. and would like to do polygon-simplification. > > Currently I use the postgis function ST_SimplifyPreserveTopology to > do the > simplification, however the dataset is growing large and I would > like to > move the pre-processing away from the database which should be busy > answering real-time queries. > > I am already doing pre-processing (parsing from list(x,y,level), > rasterisation and polygonization) in python (and distributed too, > thanks to > the new multiprocessing module). > > So, I spotted the shapely bindings for GEOS, and the thread > http://www.mail-archive.com/[email protected]/msg00510.htmlwhich > indicated that a Douglas-Peucker variant was easily accessible for me > and my pre-processing code. > > However I have checked out the trunk and not been able to "from > shapely.geos.ops import simplify", or even find the shapely.geos.ops > module
Hi, In that email, I'd suggested that in the trunk I *might* move the simplify method to a function in an ops module, or provide a complementary function. The work hasn't been done yet. Instead of using the trunk, I strongly recommend trying the 1.2 branch. Aron Bierbaum has put a lot of work into it, tests are passing, and I think we're pretty close to where we can start to consider a preview release. A geometry simplify method or its functional counterpart isn't implemented there yet, but wouldn't be much work, and would be a lot closer to being deployable than the Shapely trunk. http://svn.gispython.org/svn/gispy/Shapely/branches/1.2 Aron, what do you think about simplification for 1.2? -- Sean Gillies Programmer Institute for the Study of the Ancient World New York University _______________________________________________ Community mailing list [email protected] http://lists.gispython.org/mailman/listinfo/community
