Pieter Deleu <pieterdeleu <at> gmail.com> writes: > > Hi! > > Something funny happens to me in lnme. I don't know if it's a bug or not. > Here's a short sketch of the problem (you could skip the introduction and > just go to the models): > > I'm counting the number of spider webs ( = response variable) along two > rivers, with a two-level treatment: free-flowing and dammed. > There are three field sites (random factor) along each river, and > measurements are done six times (= random factor for repeated measurements). > > Webs are counted on four different distances along the river (fixed effect), > with six plots at each distance. > > My model looks like this: > > * > Model<-lme(Webslog1~Treatment*Distance, > random=~Week|Uniquesite/Uniqueplot,method="REML") > *
[snip] A few suggestions: (1) please give us a reproducible example -- either include your data (dput() is one way to dump it in a useful form), or post it somewhere, or make up a small data set that demonstrates the same problem. (2) it would probably be best to repost this question (with reproducible example) on r-sig-mixed-mod...@lists.r-project.org , which is specially geared toward mixed model questions. (3) you may not have your model specification quite right. For example, do you really intend to model a linear increase/decrease in the response as a function of week that varies across plots & sites? (If so, you should also probably consider a fixed effect of Week). Or do you simply want to allow plots/sites to be different (in which case you would say ~1|Uniquesite/Uniqueplot)? By the way, it's "nlme" not "lnme" Ben Bolker ______________________________________________ R-help@r-project.org 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.