Thank you, please forgive my naivety but I have tried the krigeTg and I couldnt add any cokriging formula into it (or gstat object). it seems that it only accepts the univariate formula and we cant use it for cokriging. like this:
krigeTg(V1 ~ V2, locations,newdata...... On Fri, Mar 19, 2010 at 4:45 AM, Edzer Pebesma < [email protected]> wrote: > What happens in kigeTg doesn't look that hard. Have you tried? > > Ebrahim Jahanshiri wrote: > > Thank you very much. > > However I found no couterpart for that in cokriging. Is there any way to > do > > that manually? I mean to get "m" manually? > > > > On Mon, Mar 1, 2010 at 8:26 PM, Edzer Pebesma < > [email protected] > >> wrote: > > > >> Ebrahim Jahanshiri wrote: > >> > >>> I am wondering if there is any function or option to back-transform the > >>> result of the lognormal kriging in gstat yet. > >>> > >>> > >> You can use krigeTg, which does trans-Gaussian kriging for all Box-Cox > >> transforms; passing it a lambda parameter with value 0, log-normal > kriging > >> is used. Pls look at the examples, the back-transformed values have > funny > >> names like var1TG.pred. > >> > >> The whole think has been implemented for ordinary kriging only; if > someone > >> can point me out a source that describes how to do this for universal / > >> external drift kriging, I'd be happy to look into how to implement it. > >> > >>> Although for simple kriging it is fairly straight forward, that is, it > is > >>> > >>> possible to do back-transform using the vector of predicted values and > >>> kriging variances, but for ordinary kriging, it might be difficult > because > >>> we dont have lagrange multiplier (according to my web help search) to > do > >>> the > >>> back-transformation. I am wondering if there has been any advancement > in > >>> that matter? > >>> > >>> thank you > >>> > >>> [[alternative HTML version deleted]] > >>> > >>> _______________________________________________ > >>> R-sig-Geo mailing list > >>> [email protected] > >>> https://stat.ethz.ch/mailman/listinfo/r-sig-geo > >>> > >>> > >> -- > >> Edzer Pebesma > >> Institute for Geoinformatics (ifgi), University of Münster Weseler > Straße > >> 253, 48151 Münster, Germany. Phone: +49 251 8333081, Fax: +49 251 > 8339763 > >> http://ifgi.uni-muenster.de http://www.52north.org/geostatistics > >> [email protected] > >> > >> > > > > -- > Edzer Pebesma > Institute for Geoinformatics (ifgi), University of Münster > Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251 > 8333081, Fax: +49 251 8339763 http://ifgi.uni-muenster.de > http://www.52north.org/geostatistics [email protected] > [[alternative HTML version deleted]]
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