Paulo

I think you need to provide a few more details here about how to fit

those models using your function in geoR.

* note the r_i term, which means that the replications have different

means. How would you specify this in your function ?

* I Assume the quantity of interest are the contrasts in T_j. Guess some

manual fiddling is needed to obtain confidence intervals for these

contrast ?

Alternatively, since the model is a multivariate Guassian, so it is

definetely possible to do inference by figuring out what the mean vector

and covariance matrix of the vector Y={Y_ij | i,j= ....} looks like,

write down the likelihood function and use the nlm or optim function for

maximising it.

Best regards Ole

Paulo Justiniano Ribeiro Jr wrote:

>Hi Jose

>The function likfit() in the package geoR will fit those models.

>Actually there is a data-set in the package with a similar structure

>see:

>

>require(geoR)

>data(hoef)

>help(hoef)

>

>best

>P.J.

>

>

>

>On Thu, 13 May 2004, Jose A. Hernandez wrote:

>

>

>

>>Dear R colleagues,

>>

>>My name is Jose Hernandez and work in the analysis of on-farm experiments.

>>

>>I've been a R user for sometime now, however am still struggling figuring

>>out some of my spatial analysis using R.

>>

>>Most of my experiments have the following model:

>>

>>Y_ij = Mu + r_i + T_j + e_ij

>>

>>Where:

>>r_i is some replication and T_j some fixed treatment effect.

>>

>>I many cases there is significant within block heterogeneity and therefore

>>I can't assume that e_ij are iid.

>>

>>An alternative is to use:

>>

>>Y_ij = Mu + T_j + e_ij

>>

>>And assume that:

>>

>>e_ij follows some spatial covariance model such as exponential, spherical, etc.

>>

>>

>>Are there any R packages that will integrate spatial variability into the

>>model ?

>>

>>Thanks and advance and best regards !

>>

>>Jose

>>

>>

>>--

>>Jose A. Hernandez

>>Ph.D. Candidate

>>Precision Agriculture Center

>>

>>Department of Soil, Water, and Climate

>>University of Minnesota

>>1991 Upper Buford Circle

>>St. Paul, MN 55108

>>

>>Ph. (612) 625-0445, Fax. (612) 625-2208

>>

>>_______________________________________________

>>R-sig-Geo mailing list

>>R-sig-Geo at stat.math.ethz.ch

>>

https://www.stat.math.ethz.ch/mailman/listinfo/r-sig-geo>>

>>

>>

>>

>

>Paulo Justiniano Ribeiro Jr

>Departamento de Estat?stica

>Universidade Federal do Paran?

>Caixa Postal 19.081

>CEP 81.531-990

>Curitiba, PR - Brasil

>Tel: (+55) 41 361 3471

>Fax: (+55) 41 361 3141

>e-mail: pj at est.ufpr.br

>

http://www.est.ufpr.br/~paulojus>

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>

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>

>

>

--

Ole F. Christensen

BiRC - Bioinformatics Research Center

University of Aarhus

H?egh-Guldbergs Gade 10, Building 090

DK-8000 Aarhus C

Denmark