[R] correlation in lme4

[Antonella Plaia]

Dear all,
I have tried to consider a correlation structure in lme (package lme4), but
without success.
I have used something like:

> risul<-lme(y~x+ z , data=mydata, random=~ x | g, correlation = corAR1())

but the result is the same as:

> risul<-lme(y~x+ z , data=mydata, random=~ x | g).

Can anybody help me?

Antonella


**************************************************
Prof. Antonella Plaia
Dipartimento di Scienze Statistiche e Matematiche "S. Vianelli"
Università di Palermo
Viale delle Scienze 90128 Palermo ITALIA
Tel. +39 091 6626244 Fax +39 091 485726
http://dssm.unipa.it/plaia
e-mail:plaia at unipa.it