[GRASS-stats] Nearest neighbour distance distribution but between polygons

[Rainer M Krug]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 07/05/12 14:25, Roger Bivand wrote:
> On Mon, 7 May 2012, Rainer M Krug wrote:
> 
> Hi
> 
> I have the following (presumibly simple?) question:
> 
> I have a certain number of patches (islands) in a landscape of which I need to know the
> nearest neighbour distance. As the problem is related to dispersal, I would need to know the
> actual shortest distance between the actual polygons and not only the centroids. Is there an
> easy way to obtain these in R or in GRASS? I am only aware of nearest neighbour distance
> between points.
> 

Hi Roger


>> In R, if the coordinates are projected, use gDistance(..., byid=TRUE) in the rgeos package to
>> get a matrix in the metric of the projection. If not projected, project if possible.

Exactly what I was looking for - the geometries are projected, so absolutely no problem.

Thanks a lot,

Rainer

> 
>> I don't think that the geosphere package provides for the unprojected case.
> 
>> Roger
> 
> 
> Thanks,
> 
> Rainer
> 
> 
>> _______________________________________________ grass-stats mailing list 
>> grass-stats at lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-stats
>> 
> 

- -- 
Rainer M. Krug, PhD (Conservation Ecology, SUN), MSc (Conservation Biology, UCT), Dipl. Phys.
(Germany)

Centre of Excellence for Invasion Biology
Stellenbosch University
South Africa

Tel :       +33 - (0)9 53 10 27 44
Cell:       +33 - (0)6 85 62 59 98
Fax :       +33 - (0)9 58 10 27 44

Fax (D):    +49 - (0)3 21 21 25 22 44

email:      Rainer at krugs.de

Skype:      RMkrug
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iEYEARECAAYFAk+nw0gACgkQoYgNqgF2egrVLQCfXxjpJvxuPpMMoWVHtM/IrC/9
e8AAmQHoKaGZq2gJ4WI3HIELBPxLblpo
=DOUj
-----END PGP SIGNATURE-----