Stefan; This would be a nice "wish list" to make persistent somewhere, maybe on the wiki?
On Sun, 2010-01-31 at 14:41 +0100, Stefan Keller wrote: > Dear all > > I’m preparing an introductory course about GIS and want to collect > topology functions. We’re evaluating QGIS and PostGIS and have to > be prepared that the functionality will be compared to ArcGIS/ > ArcEditor Geodatabase Topology (called topology rules there). > > Thus my question: Can anyone point me to topology functions, > most probably implements as stored procedures (pl/pgsql) and > triggers (rules)? > > I’ve compiled following “topology types” so far: > * Area topology cleaning: Eliminating sliver polygons, overshoots, > undershoots (polygon topology, same polygon class). > * Polygons are non-overlapping (polygon topology, same polygon class). > * Polygons are inside other polygons (polygon topology, two different > polygon classes). > * Line topology cleaning: Snapping close endpoints > (vertex-vertex/route topology). > * Routes that share vertices (vertex-vertex/route topology, same > line class). > * Line objects that share (inner) endpoints (node-vertex topology, > same line class). > * Line objects that are “connected to” point objects at their > (outer/inner) endpoints (node-node topology, line and point classes). > * Point objects that share points along line objects (node-vertex > topology, line and point classes). > > Pls. consider "are" (validation) as place holder to be also "should not" > (validation) or "should be snapped to" (cleaning). > > Regards, S. > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users -- Regards, Chris Hermansen · mailto:[email protected] tel+1.604.714.2878 · fax+1.604.733.0631 · mob+1.778.840.4625 Timberline Natural Resource Group · http://www.timberline.ca 401 · 958 West 8th Avenue · Vancouver BC · Canada · V5Z 1E5 _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
