[...] > > is there an easy way to derive the centre of a cloud of points ? > > > > I am aware that the set of vector points ("cloud of points") could be > > used to stake out a polygon/boundary and use v.centroid etc etc to > > derive in turn its' centroid, but I am hoping for an easier solution > > .. ? > > > > This issue stems from working with v.to.db: currently it is not > > possible to upload xy coordinates for "multiploygons" into a > > database, i.e: Within a vector layer, there might be several > > boundaries which all share the same category value. If the > > "gravitational centre/ super-centroid" for these boundaries could be > > (conveniently) calculated, the v.to.db issue could be taken care of. > > > Why not use v.dissolve on these polygons and then get the centroids of > the result ?
This option fails if the polygons don't have common borders. An example for this would be multiple polygons describing spatial exclaves of a territory/county/soil type, etc. > Another (very wild) guess: what about the mean of the coordinates of the > individual polygons' centroids ? That would be great if it could be automated. Peter > > Moritz -- Dr. Peter Löwe <[EMAIL PROTECTED]> Sensationsangebot verlängert: GMX FreeDSL - Telefonanschluss + DSL für nur 16,37 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K1308T4569a _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user