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List:       r-sig-geo
Subject:    Re: [R-sig-Geo] Variogram Plot
From:       "ONKELINX, Thierry" <Thierry.ONKELINX () inbo ! be>
Date:       2008-03-25 8:52:03
Message-ID: 2E9C414912813E4EB981326983E0A10404874A34 () inboexch ! inbo ! be
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Pujan,

We allready pointed out that geoR can't calculate the variogram of a
large dataset like yours. Use gstat instead to calculate the variogram.

Thierry 


------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research 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@inbo.be 
www.inbo.be 

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey

-----Oorspronkelijk bericht-----
Van: PUJAN RAJ REGMI [mailto:regmi_pujan@hotmail.com] 
Verzonden: zaterdag 22 maart 2008 10:14
Aan: ONKELINX, Thierry; David PINAUD; r-sig-geo@stat.math.ethz.ch
Onderwerp: RE: [R-sig-Geo] Variogram Plot


Dear all,
I think earlier i didn't clear myself. I ahve a data set of 3 colun and
14000 rows in which first and second column is X and Y coordinates and
the third column is the value of samples of each coordinates points.
Now I am trying to plot semi variogram for the given sample with respect
to the coordinate of ecah smaple data. The maximum distance in X
direction is 2.3 km and in y direction is 1.8 km. The sample are taken
12 m interval both in x and y direction in regular grid form. I hope
this time i am able to communicate.
Thanking you
Pujan
 Code:
 mol.gr <- read.table("D:/mol.dat")
 mol.gr[,"x"] <-mol.gr[,1]
 mol.gr[,"y"] <-mol.gr[,2]
 mol.gr[,"Green Band Reflectance"] <-mol.gr[,3]
 map<-as.geodata(mol.gr) # make a geoR object to use various ready-made
R unctions
 coal.var <- variog(map, max.dist =0.9) # omnidirectional semivariogram
up to half max distance
 plot(coal.var)

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