The problem is with residuals in model3. Fixed in 2.4.1 patched and later.
On Wed, 3 Jan 2007, Jarrod Hadfield wrote: > Hi, > > I'm trying to compare models, one of which has all parameters fixed > using offsets. The log-likelihoods seem reasonble in all cases except > the model in which there are no free parameters (model3 in the toy > example below). Any help would be appreciated. > > Cheers, > > Jarrod > > x<-rnorm(100) > y<-rnorm(100, 1+x) > > model1<-lm(y~x) > logLik(model1) > sum(dnorm(y, predict(model1), summary(model1)$sigma,log=TRUE)) > > # no offset - in agreement > > model2<-lm(y~offset(rep(1,100))+x-1) > logLik(model2) > sum(dnorm(y, predict(model2),summary(model2)$sigma,log=TRUE)) > > # offset and free parameters - in agreement > > model3<-lm(y~offset(rep(1,100))+offset(x)-1) > logLik(model3) > sum(dnorm(y, predict(model3),summary(model3)$sigma,log=TRUE)) > > # offset only - discrepancy > > sum(predict(model3)-c(1+x)) > > # yet predict is correct > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
