Someone asked recently about a centroid function which guaranteed that the created centroid:
1. Fell within a polygon (not outside it as is the case with implementations that average the X and Y coords of an area); 2. If the polygon is multi-part, put the centroid in the largest part. I have just such a function but it is currently Oracle PL/SQL based. It does both of the above + also have an overloaded version which will return a multi-point object wherein each point is the centroid of each disperate part in a multi-part polygon. The functions have been heavily tested with many datasets and are pretty well guaranteed to work. I also have a Java version. I do not know PostgreSQL's implementation of PL/SQL but I suspect I could convert the code pretty easily. I do not have the time at the moment to convert them but if anyone wants to download them from my website (see below) and convert them please feel free. All I ask if for a copy of the PostgreSQL implementation for hosting back on my website. regards Simon -- SpatialDB Advice and Solutions Architecture, Oracle Spatial, ArcSDE, Manifold GIS, Radius Topology and Studio Specialist. 39 Cliff View Drive, Allens Rivulet, 7150, Tasmania, Australia. Website: www.spatialdbadvisor.com Email: [EMAIL PROTECTED] Voice: +61 362 396397 Mobile: +61 418 396391 Skype: sggreener Longitude: 147.20515 Latitude: -43.01530 NAC:W80CK 7SWP3 _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
