Allan Carson <acarson <at> unbc.ca> writes: [snip] > When I try to conduct a > multiple comparison, I get an error (See below): > fm3<- lme(abovegroundbiomass.m.2~medium*amelioration*fertilizer*treatment, > random=~1|block/medium/amelioration/fertilizer) > tukeytest<-glht(fm3, linfct=mcp(treatment="Tukey")) > Error in contrMat(table(mf[[nm]]), type = types[pm]) : > less than two groups
You should probably re-post this question to the r-sig-mixed-models mailing list, which specializes (as you would guess) in mixed models. I'm a little suspicious of your random effects specification. Are there really random effects at all four levels? i.e., are there four separate hierarchical levels at which the predictors vary? It's hard to diagnose this problem without a reproducible example. Is your model fit otherwise sensible? ______________________________________________ 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.
