[GRASS-dev] point cloud analysis: new features
Benjamin Ducke
benducke at fastmail.fm
Fri Jan 9 02:45:49 PST 2015
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.
Nevertheless, since you did all that work on v.cluster in GRASS 6,
maybe it would be worth implementing this:
http://grasswiki.osgeo.org/wiki/Create_concave_hull
... in a GRASS 6 shell script?
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:
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