AFAIK lme(), by default, estimates the covariance between two or more
random-effects, thus you do not have to specify anything. You're
probably looking for something like:
fit <- lme(y ~ time * treat, random = ~ time | subject)
fit
summary(fit)
I hope it helps.
Best,
Dimitris
----
Dimitris Rizopoulos
Ph.D. Student
Biostatistical Centre
School of Public Health
Catholic University of Leuven
Address: Kapucijnenvoer 35, Leuven, Belgium
Tel: +32/(0)16/336899
Fax: +32/(0)16/337015
Web: http://med.kuleuven.be/biostat/
http://www.student.kuleuven.be/~m0390867/dimitris.htm
----- Original Message -----
From: "harry wills" <harry.wills at gmail.com>
To: <r-help at stat.math.ethz.ch>
Sent: Wednesday, June 28, 2006 9:02 AM
Subject: [R] Linear Mixed Effects
> Hi,
> I have implemented the lme in SAS and specified the random effects
> covariance structure as unstructured using the statement "random /
> type=UN"
> I want to specify same in R but not able to know how to do it.
> Can anyone please advise me on how to proceed.
> Thanks
>
>
> --
> Wills, Harry
>
> [[alternative HTML version deleted]]
>
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