On Fri, Jan 9, 2015 at 11:45 AM, Benjamin Ducke <bendu...@fastmail.fm> wrote: > On 08/01/15 23:46, Markus Metz wrote: > > [..] > >>> Thanks Markus, this is excellent progress. >>> It seems to me that the approximation of cluster shapes from grouped >>> points is a generic problem that would best be solved with a separate >>> module. As long as the shapes are roughly convex, the existing v.hull >>> should work fine. For concave shapes, AFAIK things become messy because >>> common methods such as alpha shapes require the user to provide >>> threshold values. >> >> This is true, but v.concave.hull [0] could help ;-) >> >> Markus M >> >> [0] >> https://trac.osgeo.org/grass/browser/grass-addons/grass7/vector/v.concave.hull >> > > Wow. And it's been there for a while. How could I not see that? > I think it's high time that I switch from GRASS 6 to 7.
Indeed. > > Nevertheless, since you did all that work on v.cluster in GRASS 6, > maybe it would be worth implementing this: v.cluster exists only in GRASS 7.1. It can not even be backported ti GRASS 7.0 because it relies on a new (new to GRASS) spatial index that is only available in GRASS 7.1. > > http://grasswiki.osgeo.org/wiki/Create_concave_hull > > ... in a GRASS 6 shell script? If you know Python and shell scripting, translating v.concave.hull to a shell script is easy. Otherwise, chances are good that the Python script v.concave.hull also runs with GRASS 6. Maybe some option names need to be modified. Markus M > > I am looking forward to trying the new clustering algorithms, > especially "density" and "optics2" > > Many thanks, > > Ben > > > -- > Dr. Benjamin Ducke > {*} Geospatial Consultant > {*} GIS Developer > > Spatial technology for the masses, not the classes: > experience free and open source GIS at http://gvsigce.org > _______________________________________________ > grass-dev mailing list > grass-dev@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-dev _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev