[GRASS-user] kriging with GRASS 6.2 and R

[Roger Bivand]

On Mon, 19 Feb 2007, Dr. Manuel Seeger wrote:

> Hallo all,
> 
> I'm trying to generate a DEM with kriging and trying the workout given 
> in the wiki.
> When generating the R SpatialGridDataFrame I get this error:
> Fehler in validObject(.Object) : invalid class "SpatialGridDataFrame" 
> object: invalid object for slot "data" in class "SpatialGridDataFrame": 
> got class "list", should be or extend class "data.frame"
> 
> I know, its not really a GRASS issue, but perhaps someone can help, what 
> I'm doing wrong!

The problem you have found is caused by a mismatch of R packages. Please 
update both "sp" ans "spgrass6" from CRAN - use for example 
update.packages(). I think that spgrass6 is not up to data - if it was, it 
would know that for R >= 2.4 and sp >= 0.9, it needs to provide a 
data.frame object, not a list object.

Please follow up on the STATGRASS list - there are plenty of willing and 
well-informed helpers there!

http://grass.itc.it/statsgrass/index.php

Roger


> 
> Thanks
> 
> Manuel
> 
> 

-- 
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 at nhh.no