RE: [R] nested random effects

From: Berton Gunter <gunter.berton_at_gene.com>
Date: Thu 24 Mar 2005 - 06:04:58 EST

I should have added that if you have only one Y observation per ID (within family), then the ID variance component is residual error and the model becomes (without any covariates)

Y~1, rand=~1|FAM

> On Wed, 2005-03-23 at 11:58 -0500, Shaw, Philip (NIH/NIMH) wrote:
> > Hi
> >
> > I am struggling with nested random effects and hope someone
> can help.
> >
> >
> >
> > I have individuals (ID) who are nested within families
> (FAM). I want to
> > model an outcome variable, and take account of the
> intercorrelation of
> > individuals within each family.
> >
> > I think this amounts to two random effects, one nested
> within the other.
> >
> > How can I model this in R?
> >
> > So far I have tried using the library(nlme), and then
> >
> > Y~ID, random=~1|ID*FAM,
> >
>
> An interaction random effect/fixed effect is noted as
>
> random ~1|random/fixed
>
> in your case random =~1|ID/FAM (but I don't uderstand why indiviuals
> withing families are fixed and and families are random, but there you
> go).
>
> Check out Pinheiro and Bates Ch1, especially pg 23 onwards.
>
> Cheers,
>
> F
> --
> Federico C. F. Calboli
> Department of Epidemiology and Public Health
> Imperial College, St Mary's Campus
> Norfolk Place, London W2 1PG
>
> Tel +44 (0)20 7594 1602 Fax (+44) 020 7594 3193
>
> f.calboli [.a.t] imperial.ac.uk
> f.calboli [.a.t] gmail.com
>
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R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Thu Mar 24 06:13:37 2005

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