Jorn, For your model,
model<-lme(Biomass~Age,random=~1|Age/Stand) think about nesting age in stand (doesn't that makes more sense, anyway ?). If you're lucky the NaN will zip. So, do model <- lme( Biomass ~ Age, random = ~ 1 | Stand/Age I've had a similar problem with unbalanced data when I've tried to nest Season%in%Site (which is what I wanted), with Site as a fixed effect as well. Then, like you, I've got NaN's for my Site(s). Changing the nesting to Site%in%Season has fixed the problem. However, random effects are now being specified somewhat differently. Hopefully a statistician will come in and tell you and me quite what the difference is, because I get lost in the logic of it. Note that lmer() copes with the problematic Season%in%Site nesting without problems, using the same dataset. Regards, Mark ------------------------------------------------------------ Mark DiffordPh.D. candidate, Botany Department, Nelson Mandela Metropolitan University, Port Elizabeth, SA. ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
