[R-sig-ME] complex residual variance

ONKELINX, Thierry Thierry.ONKELINX at inbo.be
Mon May 31 16:37:39 CEST 2010

Not in lmer(). But you can do it with lme() from the nlme package.


ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
team Biometrie & Kwaliteitszorg
Gaverstraat 4
9500 Geraardsbergen

Research Institute for Nature and Forest
team Biometrics & Quality Assurance
Gaverstraat 4
9500 Geraardsbergen

tel. + 32 54/436 185
Thierry.Onkelinx at inbo.be

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
~ John Tukey

> -----Oorspronkelijk bericht-----
> Van: r-sig-mixed-models-bounces at r-project.org 
> [mailto:r-sig-mixed-models-bounces at r-project.org] Namens Sven 
> De Maeyer
> Verzonden: maandag 31 mei 2010 15:47
> Aan: r-sig-mixed-models at r-project.org
> Onderwerp: [R-sig-ME] complex residual variance
> Hi all,
> I'm not a frequent user of Lme4 and I have the habit to use 
> mlwin for multilevel analyses. Nevertheless I'm willing to 
> master lme4 further.
> In my research I'm often faced with the situation where level 
> 1 variance (or residual variance in the mixed effects
> framework) isn't constant. E.g. I have longitudinal data on 
> children, with multiple measurements (observations) of these 
> children at a certain moment. As children get older these 
> measurements seem to vary more and more. So the residual 
> variance itself is a function of time. As a consequence there 
> is heteroscedasticity.  Is there a possibility to explicitly 
> model this in lme4? I know how to do it in mlwin, but is it 
> possible in lmer?
> With kind regards
> Sven De Maeyer
> _______________________________________________
> R-sig-mixed-models at r-project.org mailing list 
> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models

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