structure of a lmer code

Hi Antoine,

I think you want

fm2<-lmer(log(y)~-1+x+(-1+x|group), na.action="na.omit", data=...)

no?

Best,
Ista
2012/3/28 Antoine TARDIF <antoine.tardif at usherbrooke.ca>:

Dear all,

I would like to fit a multilevel linear model, with varying slope but
with intercepts fixed at zero (in my experiment, all the samples have
the same value at time=0).

I have both nested and non-nested factors, but in a first step, we
would like to fit a lmer model "fm2" equivalent to this lme model
"fm1" :

library(nlme)
fm1<-lme(log(y)~x, random=~-1+x|group, na.action="na.omit", data=...)

I tried this code for the lmer function :
library(lme4)
fm2<-lmer(log(y)~-1+x+(-1+y|group), na.action="na.omit", data=...)

1. Instead of providing similar results to fm1, fm2 results do not
make sense. Is there a mistake in the structure of the fm2 code ?

2. I also have an other question :

?> coef(fm1) works, but
?> coef(fm2) shows this error message : "unable to align random and
fixed effects"

What does it mean ?

If someone could help me, thanks a lot in advance..

Antoine Tardif

--
? ? ?Antoine TARDIF
? D?partement de Biologie
? Universit? de Sherbrooke
? Sherbrooke (Qc)
? J1K 2R1 Canada

? Bureau D5-0204
? (+ 1) 819 821 8000 poste 61928
? antoine.tardif at usherbrooke.ca


? ? ? ?[[alternative HTML version deleted]]