If you like, we can iterate to a working example from passing
the vector points to R from GRASS, doing the modelling and
kriging predictions, and passing the prediction rasters back
to GRASS, but I'd like input from users to make the description sound.
As a novice to this topic (exactly, I'm right now trying to dig into
it), this would be a great idea.
Best regards,
Olaf Vellinga
--
Wageningen UR
Alterra
Centre for Water & Climate
Team Land-Atmosphere Interactions
Address: www.sense.nl/researchers/vellinga
Global Met-Pages: www.globalmetpages.net
-----Original Message-----
From: owner-GRASSLIST@baylor.edu
[mailto:owner-GRASSLIST@baylor.edu] On Behalf Of Roger Bivand
Sent: maandag 23 januari 2006 13:15
To: ivan marchesini
Cc: grasslist-en
Subject: [GRASSLIST:9953] Re: R, kriging and grass6On Mon, 23 Jan 2006, ivan marchesini wrote:
> Hi to all...
> we are triyng to use kriging using R and grass6, We have
seen a lot of
> documentation about R and GRASS5 but not so many about grass6...
> the problem is that we are trying to do an interpolation using the
> functions gmeta6 and kriging...
> if we are not wrong, the R library GRASS is developed for
grass5 and
> inside there is the function krige.G that use the location data
> acquired using the gmeta() function...
> the problem is that we have found the gmeta6() function but not the
> krige.G6 function and obvously the krige.G doesn't work using the
> location data of grass6 (obtained using gmeta6)
>
> how can we simply solve this problem....krige.G was a nasty hack, and should best be forgotten. The
direct route is to use the sp classes in R and implemented
for GRASS in spgrass6 - see GRASS News for the GRASS side and
R News for the R side, combined with a proper R geostats
package. Of those available, gstat is tightly bound to sp
classes, so as far as I know, the only bit that needs doing
by hand is to create a GridTopology object, or a SpatialGrid
object, from the data returned by gmeta6() to pass to the
kriging prediction function.If you like, we can iterate to a working example from passing
the vector points to R from GRASS, doing the modelling and
kriging predictions, and passing the prediction rasters back
to GRASS, but I'd like input from users to make the description sound.Best wishes,
Roger
>
> thank you
>
> Ivan
>
>
>
>--
Roger Bivand
Economic Geography Section, Department of Economics,
Norwegian School of Economics and Business Administration,
Helleveien 30, N-5045 Bergen, Norway. voice: +47 55 95 93 55;
fax +47 55 95 95 43
e-mail: Roger.Bivand@nhh.no