R help - Oct 2007 - is there a similar function to perform repeated statements as in SAS PROC MIXED?

PROC MIXED is used to fit mixed effects model for correlated data.

Usually we can use either a REPEATED statment or a RANDOM statement.

The random statement is corresponding to lme function in R -- specifying a
random effect term.

The repeated statement actually directly specifies the covariance structure
-- is there a similar function in R to do this? I currently want to specify
a unstructured matrix. (Of course if i just want to use compound symmetry, i
know i can still use lme.)

	[[alternative HTML version deleted]]

you can wave a look at the gls() function in package nlme, and 
specifically at the `weights' and `correlation' arguments; the same 
arguments are also available in the lme() function.

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: "gallon li" <gallon.li at gmail.com>
To: "r-help" <r-help at stat.math.ethz.ch>
Sent: Wednesday, October 24, 2007 2:43 PM
Subject: [R] is there a similar function to perform repeated 
statements asin SAS PROC MIXED?

> PROC MIXED is used to fit mixed effects model for correlated data.
>
> Usually we can use either a REPEATED statment or a RANDOM statement.
>
> The random statement is corresponding to lme function in R --  
> specifying a
> random effect term.
>
> The repeated statement actually directly specifies the covariance 
> structure
> -- is there a similar function in R to do this? I currently want to 
> specify
> a unstructured matrix. (Of course if i just want to use compound 
> symmetry, i
> know i can still use lme.)
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide 
> http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 

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