[R] Re: geoR size limit problem

[Miha STAUT]

>Dear Miha (cc: Paulo Ribeiro [the developer of geoR, who is not subscribed 
>to R-help])
>
>Some reproducible code would help here.

Unfortunately I do not have an internet connect on my computer, that is why 
I did every thing very descriptive. Anyway I will try:

str(df)
   [#approx 2500]
$ x ...
$ y ...
$ z ...
library(geoR)
g<-as.geodata(df)
expvar<-variog(g, uvec=seq(0,1000,25), option="bin")
matern<-variofit(expvar, ini=c(1600,300), cov.model="matern", fix.nug=T, 
nug=25, kappa=1.5, max.dist=800, weights="npairs")

library(GRASS)
G<-gmeta()
grid<-expand.matrix(G$xseq,G$yseq)
length(G$xseq)
900 #approx
length(G$yseq)
650 #approx
krige.matern<-krige.conv(g, loc=grid, krige=krige.control(obj.m=matern, 
type="OK"))

#5 min processing
can not allocate vector of 1500000000 #approx

Thanks, Miha Staut

>
>Guessing :
>
>* geoR does not implement kriging with local neighbourhoods, but instead 
>conditions on all data. Therefore having 2500 data points would imply 
>having a covariance matrix of size 2500*2500 approx 6million . Not sure if 
>this is too much, but I do not think so.