[R-sig-Geo] pseudo R-squared with likfit (geoR)

[Paulo Justiniano Ribeiro Jr]

Marion

In your code you compute objects sp07*
but uses others sp07* to compute the pseudo-R2 - would be that the 
problem?

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
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e-mail: paulojus AT  ufpr  br
http://www.leg.ufpr.br/~paulojus

On Wed, 7 Nov 2012, Marion Jacquot wrote:

> We want to compute a pseudo R-squared for a model whose parameter
> estimation was based on maximum likelihood (function likfit, package geoR).
>
> I tried to compute the R2 proposed by Maddala (1983) which compare the
> maximized likelihood for the model without any predictor and the
> maximized likelihood for the model with all predictors.
> I got a really low value (0,01%). Did I miss something? Are there other
> R-squared which are more appropriate than the R2 of Maddala? :
>
> >sp05_l01 <- likfit(cnm05g, *ini.cov.pars=vm05*, lik.method = "REML",
>                    trend = trend.spatial(~ logIKA04 + nbLitre0 +
> nbLitre1, cnm05g))#complete model
> >sp05_nt <- update(sp05_01, trend = trend.spatial("cte", cnm05g))
> #null model
>
> >1-(sp07_nt$loglik/sp07_l0$loglik)^(2/590)#Maddala (1983)
> [1] 0.0001510074
>
> Thanks,
> Regards,
> Marion
>
> -- 
> Marion Jacquot
> Laboratoire de Chrono-environnement
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>
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