[R-sig-Geo] variograms do not satisfy a legal model

[ONKELINX, Thierry]

Edzer,

Could you tell me how to override this check? I have been reading the
helpfile but I can't find it.

Thanks,

Thierry

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Reseach Institute for Nature
and Forest
Cel biometrie, methodologie en kwaliteitszorg / Section biometrics,
methodology and quality assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium
tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be
www.inbo.be 

Do not put your faith in what statistics say until you have carefully
considered what they do not say.  ~William W. Watt
A statistical analysis, properly conducted, is a delicate dissection of
uncertainties, a surgery of suppositions. ~M.J.Moroney

 

> -----Oorspronkelijk bericht-----
> Van: Edzer J. Pebesma [mailto:e.pebesma at geo.uu.nl] 
> Verzonden: maandag 7 mei 2007 17:00
> Aan: ONKELINX, Thierry
> CC: r-sig-geo at stat.math.ethz.ch
> Onderwerp: Re: [R-sig-Geo] variograms do not satisfy a legal model
> 
> Thierry, you'll have to find out what the linear model of 
> regionalization or intrinsic correlation mean; they are legal 
> models, meaning that they lead to predictions with guaranteed 
> non-negative prediction variances. There's a way to override 
> the check (meaning it will not stop on error) but not to get 
> that guarantee.
> --
> Edzer
> 
> ONKELINX, Thierry wrote:
> > Dear useRs,
> >
> > I'm trying to do some cokriging. I try fit the variograms 
> with fit.lmc 
> > (gstat package).
> >
> > #Problem 1: how to get the model in an elegant way into the gstat 
> > object? This is how I do it now.
> > library("gstat")
> > data(meuse)
> > g <- gstat(id = "ln.zinc", formula = log(zinc)~1, locations = ~x+y, 
> > data = meuse) g <- gstat(g, id = "ln.lead", formula = log(lead)~1, 
> > locations = ~x+y, data = meuse) #fit the variogram models using 
> > fit.lmc model <- fit.lmc(variogram(g), g, model = vgm(.55, 
> "Sph", 900, 
> > .05), fit.ranges = FALSE) g <- gstat(g, id = "ln.zinc", model = 
> > model[["model"]][["ln.zinc"]]) g <- gstat(g, id = 
> "ln.lead", model = 
> > model[["model"]][["ln.lead"]]) g <- gstat(g, id = c("ln.zinc", 
> > "ln.lead"), model =
> > model[["model"]][["ln.zinc.ln.lead"]])
> > predict(g, newdata = meuse)
> >
> > #Problem 2. the gstat object doesn't accept different 
> ranges. Or am I 
> > doing something wrong?
> > library("gstat")
> > data(meuse)
> > g <- gstat(id = "ln.zinc", formula = log(zinc)~1, locations = ~x+y, 
> > data = meuse) g <- gstat(g, id = "ln.lead", formula = log(lead)~1, 
> > locations = ~x+y, data = meuse) # examine variograms and cross 
> > variogram:
> > plot(variogram(g))
> > # enter direct variograms:
> > g <- gstat(g, id = "ln.zinc", model = vgm(.55, "Sph", 800, 
> .05)) g <- 
> > gstat(g, id = "ln.lead", model = vgm(.55, "Sph", 900, .05)) # enter 
> > cross variogram:
> > g <- gstat(g, id = c("ln.zinc", "ln.lead"), model = vgm(.47, "Sph", 
> > 900,
> > .03))
> > predict(g, newdata = meuse)
> > # Error in predict.gstat(g, newdata = meuse) : gstat: value not 
> > allowed
> > for: variograms do not satisfy a legal model
> >
> > Thanks,
> >
> > Thierry
> >
> > 
> ----------------------------------------------------------------------
> > --
> > ----
> > ir. Thierry Onkelinx
> > Instituut voor natuur- en bosonderzoek / Reseach Institute 
> for Nature 
> > and Forest Cel biometrie, methodologie en kwaliteitszorg / Section 
> > biometrics, methodology and quality assurance Gaverstraat 4 9500 
> > Geraardsbergen Belgium tel. + 32 54/436 185 
> Thierry.Onkelinx at inbo.be 
> > www.inbo.be
> >
> > Do not put your faith in what statistics say until you have 
> carefully 
> > considered what they do not say.  ~William W. Watt A statistical 
> > analysis, properly conducted, is a delicate dissection of 
> > uncertainties, a surgery of suppositions. ~M.J.Moroney
> >
> > _______________________________________________
> > R-sig-Geo mailing list
> > R-sig-Geo at stat.math.ethz.ch
> > https://stat.ethz.ch/mailman/listinfo/r-sig-geo
> >   
> 
>