[R-sig-Geo] Performing a kriging

[Paulo Justiniano Ribeiro Jr]

The iitial values at the ini argumento for likfit seems innapropriate for 
your data.
some reasonable guesses for them would be

var(Humidity) and 0.05*max(dist(cbind(X,Y)))

Besides consider divide UTM values by 1000 expressing distance in km
to avoid computations with large numbers




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 Thu, 13 Jun 2013, Komine wrote:

> Dear,
> I use the data (.csv) shown below for performing a kriging.
>       X             Y       Humidity
> 1 719134.1 1433671       90
> 2 736867.3 1431585       50
> 3 751471.1 1422197       32
> 4 749384.8 1414895       75
> 5 732694.8 1413851       12
> 6 719134.1 1412808       65
>
> I use this code retreived from internet and adapted with my data.
>
>> tab<-read.table("C:\\Users\\Kriging.csv",sep=";",dec=",",header=TRUE)
>> tab
>> library(geoR)
>> ml <- likfit(Kriging, ini = c(1,0.5), fix.nugget =T)
>> pred.grid <-  expand.grid(seq(0,1, l=51), seq(0,1, l=51))
>> kc <- krige.conv(Kriging, loc = pred.grid, krige = krige.control(obj.m =
>> ml))
>> image(kc, loc = pred.grid, col=gray(seq(1,0.1,l=30))
>
> When I run the code, I have an error message from the fourth command line.
>
> Thank you in advance for your advice, I am not familiar with in spatial
> statistics.
>
> Komine
>
>
>
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