Dear Kapo
I've replied your private message with some details
Let me add the "honouring the points" will dependes on which
interpretation is given to the nugget (micro-scale variation measurement
error or a combination of these)
In geoR there are arguments micro.scale and signal in n
krige.control() and output.control() respectivelly, to control such
behaviour
Paulo Justiniano Ribeiro Jr
LEG (Laboratorio de Estatistica e Geoinformacao)
Universidade Federal do Parana
Caixa Postal 19.081
CEP 81.531-990
Curitiba, PR - Brasil
Tel: (+55) 41 3361 3573
VOIP: (+55) (41) (3361 3600) 1053 1066
Fax: (+55) 41 3361 3141
e-mail: paulojus AT ufpr br
http://www.leg.ufpr.br/~paulojus
On Sat, 13 Nov 2010, kapo coulibaly wrote:
I?m using geoR to interpolate hydraulic conductivities. I constructed the
variogram using the log transform as follows:
dummy.var<-variog(dummy.geo,max.dist=40000,uvec=25,lambda=0) # Then I
fitted a spherical model using eyefit parameters as starting parameters
dummy.param<-eyefit(dummy.var)
param1<-variofit(vario=dummy.var, ini.cov.pars=dummy.param[[1]]$cov.pars,
cov.model = dummy.param[[1]]$cov.model,nugget=dummy.param[[1]]$nugget)
spatPara<-krige.control(type.krige="ok",obj.model=param1)
# I then interpolate across the map
InterMap<-krige.conv(dummy.geo,loc=loc,krige=spatPara)
Ma question is why are my interpolated values higher than the actual
measurements. I expected the interpolation to honour measurement points at
least. Am I missing something?
Thanks
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