Re: [R-sig-Geo] [Gstat-info] LOCAL universal kriging with GLOBAL reg. coeff. estimation

2008-08-21 Thread Edzer Pebesma
Good question, I'll include r-sig-geo as well. actually the prediction equations you end up with are kind of funny, and I've never seen them written out. Two different covariance matrices being inversed. Package gstat can do the two-step approach: global BLUE, then simple kriging of

Re: [R-sig-Geo] Spatial Error Model - ANOVA table

2008-08-21 Thread Roger Bivand
On Wed, 20 Aug 2008, Samuel Field wrote: List, Is it possible to decompose the variance of an outcome into trend, signal and noise components using a SAR model - analogous to what one would get with an OLS model? This doesn't seem to be straight forward. With OLS, we decompose Y into two

Re: [R-sig-Geo] variogram question

2008-08-21 Thread Pilar Tugores Ferra
I would add Ordinary Least Squares (It may be the same as your SS), Weighted Least Squares, Maximum Likelihood and Restricted Maximum Likelihood. These four methods are available in the function likfit of the package geoR. I've been using it a little bit and I think sometimes one method works

Re: [R-sig-Geo] [Gstat-info] LOCAL universal kriging with GLOBAL reg. coeff.estimation

2008-08-21 Thread Tomislav Hengl
Dear Radim, Edzer, I was thinking about the same problem few years ago (I assume that you work with auxiliary maps and not only coordinates). I think (have a feeling) that local and global Universal kriging should be treated as two things (especially if you put a very narrow search radius).

[R-sig-Geo] [Spam]: how to get numerical val ues of a variogram

2008-08-21 Thread Pilar Tugores Ferra
Hello everybody! For sure it is very simple, but I can't find the way. How could I obtain the numerical values of a experimental semivariogram or variogram? Is it any function that makes this in geoR or gstat (or out of them)? Thanks! Pilar Mª Pilar Tugores Ferrà Becaria FPI - PhD Student