[R] [Fwd: Ordinary and simple kriging]

[Juan Zwolinski]

Juan Zwolinski wrote:
> 
> I'm performing ordinary and simple kriging from a set of non-negative
> values:
> 
> 
> >krige.control.sk<-krige.control(type.krige="sk",obj.model=my.variogram.model,beta=my.variogram.model$beta)
> 
> >sk<-krige.conv(cadiz.geo,data=amostragem.cadiz$dia1.std,locations=as.matrix(cadiz.polygrid[,c(1,2)]),krige=krige.control.sk)
> krige.conv: model with constant mean
> krige.conv: Kriging performed using global neighbourhood
> 
> and
> 
> >krige.control.ok<-krige.control(type.krige="ok",obj.model=my.variogram.model)
> 
> >ok<-krige.conv(cadiz.geo,data=amostragem.cadiz$dia1.std,locations=as.matrix(cadiz.polygrid[,c(1,2)]),krige=krige.control.ok)
> krige.conv: model with constant mean
> krige.conv: Kriging performed using global neighbourhood
> 
> where my.variogram.model is gaussian fitted through variofit with
> "cressie" weigths.
> 
> I'm getting the same predicted values for both models, 12%  of them
> being negative. Is it because simple and ordinary kriging predictions
> are not including the overall mean? If this is the case what mean should
> I use?

Thank you for your help
Juan
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