Dear list,



I am trying to fit some mixed models using packages lme4 and nlme.

I did the model selection using lmer but I suspect that I may have some
autocorrelation going on in my data so I would like to have a look using the
handy correlation structures available in nlme.



The problem is that I cannot translate my lmer model to lme:


mod1<- lmer(y~x + (1|a:b) + (1|b:c), data=mydata)


"a", "b" and "c" are factors with "c" nested in "b" and "b" nested in "a"


The best I can do with lme is:



mod2<- lme(y~x, random=list(a=~1, b=~1, c=~1), data=mydata)



which is the same as:



lmer(y~x + (1|a) + (1|a:b) + (1|a:b:c), data=mydata)



I am not at all interested in random effects (1|a) and (1|a:b:c) as they are
not significant. I just need two random intercepts as specified in mod1. How
can I translate mod1 into lme language?



Any help on this would be much appreciated.



Jonas

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