[R-sig-Geo] space-time kriging

[Pınar Aslantas Bostan]

Hi Edzer,

Thank you for your mail. 
Prec data has location and time information. 

> prec_data[1:10,] 
   Station      X       Y   Prec Year Month Day
1    17020 693894 4931348 1274.4 1970     1   1
2    17020 693894 4931348 1134.3 1971     1   1
3    17020 693894 4931348  940.7 1972     1   1
4    17020 693894 4931348 1253.3 1973     1   1
5    17020 693894 4931348  940.8 1974     1   1
6    17020 693894 4931348  913.4 1975     1   1
7    17020 693894 4931348  895.3 1976     1   1
8    17020 693894 4931348  803.5 1977     1   1
9    17020 693894 4931348  993.1 1978     1   1
10   17020 693894 4931348  976.4 1979     1   1


-----Original Message-----
From: r-sig-geo-bounces at r-project.org [mailto:r-sig-geo-bounces at r-project.org] On Behalf Of Edzer Pebesma
Sent: Friday, July 01, 2011 2:50 PM
To: r-sig-geo at r-project.org
Subject: Re: [R-sig-Geo] space-time kriging

Hi Pinar,

as you say, some data are missing, but the way you create index suggests
none are missing. Does your table "prec" have information for each
observation on which location and at which time it has been taken? Could
you maybe show how prec[1:10,] looks like?

Wbr,

On 07/01/2011 01:12 PM, Pınar Aslantas Bostan wrote:
> Dear all,
> 
>  
> 
> I am working about space-time (ST) kriging. I want to make ST ordinary
> kriging with sparse data set. Dependent data is annual precipitation
> measured from 257 meteorological station. Observation period starts from
> 1970 and finishes at 2008, so temporal entity of my study contains 39
> year-value. Precipitation data comprised from 5365 value. It is not equal to
> 257 (location) *39 (time), because some stations has no value for some
> years. Therefore my data set fits to STSDF. An index table is required for
> STSDF object. But I could not create correct index object, my code does not
> work. 
> 
>  
> 
> I tried to summarize my code:
> 
>  
> 
> # creating STSDF object
> 
>  
> 
> # sp is spatial entity (257 spatial location)
> 
> # time is temporal entity (39 year period)
> 
> # prec is data attribute (5365 number of annual precipitation value)
> 
>  
> 
> index <- as.matrix(expand.grid(1:length(sp),1:nrow(time)))
> 
> w= STSDF(sp, time, data.frame(values = as.vector(t(prec))),index)
> 
>  
> 
> Error: nrow(object at index) == nrow(object at data) is not TRUE
> 
>  
> 
> Can you please help me about this error, how can I create correct index
> object?
> 
>  
> 
> Thank you all in advance!
> 
> With my best regards,
> 
> Pinar
> 
>  
> 
>  
> 
> Pinar Aslantas Bostan
> 
> Research Assistant
> 
> Department of Geodetic and
> 
> Geographic Information Technologies (GGIT) Middle East Technical University
> 
> 06531 Ankara/TURKEY
> 
> aslantas at metu.edu.tr
> 
>  
> 
> 
> 	[[alternative HTML version deleted]]
> 
> _______________________________________________
> R-sig-Geo mailing list
> R-sig-Geo at r-project.org
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-- 
Edzer Pebesma
Institute for Geoinformatics (ifgi), University of Münster
Weseler Straße 253, 48151 Münster, Germany. Phone: +49 251
8333081, Fax: +49 251 8339763  http://ifgi.uni-muenster.de
http://www.52north.org/geostatistics      e.pebesma at wwu.de

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