[R-sig-Geo] GSTAT: Optimize power value for IDW

[Paul Hiemstra]

Zev Ross wrote:
> Hi All,
>
> ArcGIS has a nice little button that calculates the optimal power 
> value to use for inverse distance weighting based on cross-validation 
> and RMSPE. Just wondering if anyone had written something similar in R 
> -- I'm using GSTAT and I'd like to avoid back and forth with ArcGIS 
> (and obviously I'd like to avoid writing it myself as well!).
>
> Zev
>
Hi Zev,

It seems to me that you want to perform some kind of optimal automatic 
interpolation. As an alternative to the methods presented by Alessandro, 
Edzer and myself you could try the automap package I wrote for my PhD. 
It provides a means of automatically performing kriging (in my view 
superior to IDW, for example it takes clustering of observations into 
account; it provides an estimate of prediction uncertainty). The package 
is not yet available from CRAN, but the latest version can be downloaded 
from my website:

http://intamap.geo.uu.nl/~paul/Downloads.html

There is a .zip binary file for Windows and a .tar.gz file for Linux. 
After loading the package, the command demo(automap) will give you a 
good impression of the package. Any feedback on the documentation and 
structure of the package is most welcome.

cheers,
Paul

-- 
Drs. Paul Hiemstra
Department of Physical Geography
Faculty of Geosciences
University of Utrecht
Heidelberglaan 2
P.O. Box 80.115
3508 TC Utrecht
Phone: 	+31302535773
Fax:	+31302531145
http://intamap.geo.uu.nl/~paul