[R] Variance Components in R

Spencer Graves spencer.graves at pdf.com
Thu Aug 17 17:59:29 CEST 2006


Hi, Iuri: 

      If you've got an 8086 AND a huge data set, compute time might be a 
problem with 'lmer'.  However, if you a reasonably modern computer and 
only a a few thousand observations, 'lmer' should complete almost in the 
blink of an eye -- or at least in less time than it would talk for a cup 
of coffee. 

      Spencer

Doran, Harold wrote:
> This will (should) be a piece of cake for lmer. But, I don't speak SPSS.
> Can you write your model out as a linear model and give a brief
> description of the data and your problem?
>  
> In addition to what Spencer noted as help below, you should also check
> out the vignette in the mlmRev package. This will give you many
> examples.
>  
> vignette('MlmSoftRev')
>  
>  
>  
>
>
> ________________________________
>
> 	From: prof.iuri at gmail.com [mailto:prof.iuri at gmail.com] On Behalf
> Of Iuri Gavronski
> 	Sent: Thursday, August 17, 2006 11:16 AM
> 	To: Doran, Harold
> 	Subject: Re: [R] Variance Components in R
> 	
> 	
> 	9500 records. It didn`t run in SPSS or SAS on Windows machines,
> so I am trying to convert the SPSS script to R to run in a RISC station
> at the university.
> 	
> 	
> 	On 8/17/06, Doran, Harold <HDoran at air.org> wrote: 
>
> 		Iuri: 
> 		
> 		The lmer function is optimal for large data with crossed
> random effects.
> 		How large are your data?
> 		
> 		> -----Original Message-----
> 		> From: r-help-bounces at stat.math.ethz.ch 
> 		> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of
> Iuri Gavronski
> 		> Sent: Thursday, August 17, 2006 11:08 AM
> 		> To: Spencer Graves
> 		> Cc: r-help at stat.math.ethz.ch
> 		> Subject: Re: [R] Variance Components in R
> 		>
> 		> Thank you for your reply.
> 		> VARCOMP is available at SPSS advanced models, I'm not
> sure 
> 		> for how long it exists... I only work with SPSS for
> the last
> 		> 4 years...
> 		> My model only has crossed random effects, what perhaps
> would
> 		> drive me to lmer().
> 		> However, as I have unbalanced data (why it is normally
> called 
> 		> 'unbalanced design'? the data was not intended to be
> 		> unbalanced, only I could not get responses for all
> cells...),
> 		> I'm afraid that REML would take too much CPU, memory
> and time
> 		> to execute, and MINQUE would be faster and provide
> similar 
> 		> variance estimates (please, correct me if I'm wrong on
> that point).
> 		> I only found MINQUE on the maanova package, but as my
> study
> 		> is very far from genetics, I'm not sure I can use this
> package.
> 		> Any comment would be appreciated. 
> 		> Iuri
> 		>
> 		> On 8/16/06, Spencer Graves <spencer.graves at pdf.com>
> wrote:
> 		> >
> 		> >       I used SPSS over 25 years ago, but I don't
> recall
> 		> ever fitting a
> 		> > variance components model with it.  Are all your
> random
> 		> effects nested?
> 		> > If they were, I would recommend you use 'lme' in the
> 'nlme' package.
> 		> > However, if you have crossed random effects, I
> suggest you 
> 		> try 'lmer'
> 		> > associated with the 'lme4' package.
> 		> >
> 		> >       For 'lmer', documentation is available in
> Douglas
> 		> Bates. Fitting
> 		> > linear mixed models in R. /R News/, 5(1):27-30, May
> 2005 
> 		> > (www.r-project.org -> newsletter).  I also recommend
> you try the
> 		> > vignette available with the 'mlmRev' package (see,
> e.g.,
> 		> >
> http://finzi.psych.upenn.edu/R/Rhelp02a/archive/81375.html).
> 		> >
> 		> >        Excellent documentation for both 'lme' (and
> indirectly for
> 		> > 'lmer') is available in Pinheiro and Bates (2000)
> 		> Mixed-Effects Models
> 		> > in S and S-Plus (Springer).  I have personally
> recommended
> 		> this book
> 		> > so many times on this listserve that I just now got
> 234 hits for
> 		> > RSiteSearch("graves pinheiro").  Please don't
> hesitate to pass this 
> 		> > recommendation to your university library.  This
> book is
> 		> the primary
> 		> > documentation for the 'nlme' package, which is part
> of the
> 		> standard R
> 		> > distribution.  A subdirectory
> "~library\nlme\scripts" of your R 
> 		> > installation includes files named "ch01.R",
> "ch02.R", ...,
> 		> "ch06.R",
> 		> > "ch08.R", containing the R scripts described in the
> book.  These R
> 		> > script files make it much easier and more enjoyable
> to study that 
> 		> > book, because they make it much easier to try the
> commands
> 		> described
> 		> > in the book, one line at a time, testing
> modifications to check you
> 		> > comprehension, etc.  In addition to avoiding
> problems with 
> 		> > typographical errors, it also automatically
> overcomes a few
> 		> minor but
> 		> > substantive changes in the notation between S-Plus
> and R.
> 		> >
> 		> >       Also, the "MINQUE" method has been obsolete
> for over 
> 		> 25 years.
> 		> > I recommend you use method = "REML" except for when
> you want to
> 		> > compare two nested models with different fixed
> effects;  in
> 		> that case,
> 		> > you should use method = "ML", as explained in
> Pinheiro and 
> 		> Bates (2000).
> 		> >
> 		> >       Hope this helps.
> 		> >       Spencer Graves
> 		> >
> 		> > Iuri Gavronski wrote:
> 		> > > Hi,
> 		> > >
> 		> > > I'm trying to fit a model using variance
> components in R, but if 
> 		> > > very new on it, so I'm asking for your help.
> 		> > >
> 		> > > I have imported the SPSS database onto R, but I
> don't know how to
> 		> > > convert the commands... the SPSS commands I'm
> trying to 
> 		> convert are:
> 		> > > VARCOMP
> 		> > >    RATING BY CHAIN SECTOR RESP ASPECT ITEM
> 		> > >    /RANDOM = CHAIN SECTOR RESP ASPECT ITEM
> 		> > >    /METHOD = MINQUE (1)
> 		> > >    /DESIGN = CHAIN SECTOR RESP ASPECT ITEM 
> 		> > >                SECTOR*RESP SECTOR*ASPECT
> SECTOR*ITEM CHAIN*RESP
> 		> > > CHAIN*ASPECT CHAIN*ITEM RESP*ASPECT RESP*ITEM
> 		> > >                SECTOR*RESP*ASPECT SECTOR*RESP*ITEM
> 		> CHAIN*RESP*ASPECT 
> 		> > >    /INTERCEPT = INCLUDE.
> 		> > >
> 		> > > VARCOMP
> 		> > >    RATING BY CHAIN SECTOR RESP ASPECT ITEM
> 		> > >    /RANDOM = CHAIN SECTOR RESP ASPECT ITEM
> 		> > >    /METHOD = REML 
> 		> > >    /DESIGN = CHAIN SECTOR RESP ASPECT ITEM
> 		> > >                SECTOR*RESP SECTOR*ASPECT
> SECTOR*ITEM CHAIN*RESP
> 		> > > CHAIN*ASPECT CHAIN*ITEM RESP*ASPECT RESP*ITEM
> 		> > >                SECTOR*RESP*ASPECT SECTOR*RESP*ITEM
>
> 		> CHAIN*RESP*ASPECT
> 		> > >    /INTERCEPT = INCLUDE.
> 		> > >
> 		> > > Thank you for your help.
> 		> > >
> 		> > > Best regards,
> 		> > >
> 		> > > Iuri. 
> 		> > >
> 		> > > _______________________________________
> 		> > > Iuri Gavronski - iuri at ufrgs.br
> 		> > > doutorando
> 		> > > UFRGS/PPGA/NITEC - www.ppga.ufrgs.br Brazil
> 		> > >
> 		> > > ______________________________________________
> 		> > > R-help at 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
> 		> > > and provide commented, minimal, self-contained,
> reproducible code.
> 		> > >
> 		> >
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