pseudo R-squared with likfit (geoR)
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 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 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 UMR UFC/CNRS 6249 USC INRA Universit? de Franche-Comt? Place Leclerc F-25030 Besan?on cedex FRANCE Tel. : +33 (0)381 665 829 Fax : +33 (0)381 665 797 http://chrono-environnement.univ-fcomte.fr/ [[alternative HTML version deleted]]