am trying to perform a linear mixed model via R. I have a SAS code existing and I am trying to translate it in R.
Here is my data: 2 groups products: treated, témoin 5 times: T0, T1, T2, T4 et T6 vol (Subjets) = 12 Subjets 1 response : y
Here is my SAS code:
proc mixed data =toto method= ML;
class = traitement temps vol ;
model y= traitement temps traitement*temps /ddfm=kr outp=residuals;
repeated traitement*temps / subject =vol type=ar(1) group=traitement*temps;
lsmeans traitement*temps / pdiff= all cl;
run;
and here is my R code:
mod<-nlme::lme(y ~ temps*traitement,
data=data,
random = ~ traitement | id,
correlation =corCAR1(form = ~ temps | id/traitement),
method="ML" ,contrasts=list(traitement="contr.sum" ))
ls.m<-lsmeans(mod,list(pairwise ~ temps|traitement,
pairwise ~ traitement|temps))
summary(glht(mod, linfct=mcp(traitement="Dunnett")))
contrastes<- pairs(ls.m)
AIC and BIC are differents: and my R model is differents, no same p-values ...
Have you any ideas ?
Many thanks !!