# Re: [R] extracting nested variances from lme4 model

From: Spencer Graves <spencer.graves_at_pdf.com>
Date: Sun 15 Oct 2006 - 02:00:06 GMT

> tapply(dtf\$x, dtf\$trth, sd)
FALSE TRUE
1.532251 8.378206

Since var(x[trth]) > var(x[!trth]), I thought that the following should produce this:

mod1.<-lmer( x ~ (1|rtr)+ (trth|cs) , data=dtf)

Unfortunately, this generates an error for me:

Error in lmer(x ~ (1 | rtr) + (trth | cs), data = dtf) :

If we are lucky, someone else might educate us both.

I'm sorry I couldn't answer your question, but I hope these comments might help in some way.

Spencer Graves

Frank Samuelson wrote:
> I have a model:
> mod1<-lmer( x ~ (1|rtr)+ trth/(1|cs) , data=dtf) #
>
> Here, cs and rtr are crossed random effects.
> cs 1-5 are of type TRUE, cs 6-10 are of type FALSE,
> so cs is nested in trth, which is fixed.
> So for cs I should get a fit for 1-5 and 6-10.
>
> This appears to be the case from the random effects:
> > mean( ranef(mod1)\$cs[[1]][1:5] )
> [1] -2.498002e-16
> > var( ranef(mod1)\$cs[[1]][1:5] )
> [1] 23.53083
> > mean( ranef(mod1)\$cs[[1]][6:10] )
> [1] 2.706169e-16
> > var( ranef(mod1)\$cs[[1]][6:10] )
> [1] 1.001065
>
> However VarCorr(mod1) gives me only
> a single variance estimate for the cases.
> How do I get the other variance estimate?
>
> Thanks for any help.
>
> -Frank
>
>
>
> My fake data set:
> -------------------------------------------
> data:
> \$frame
> x rtr trth cs
> 1 -4.4964808 1 TRUE 1
> 2 -0.6297254 1 TRUE 2
> 3 1.8062857 1 TRUE 3
> 4 2.7273275 1 TRUE 4
> 5 -0.6297254 1 TRUE 5
> 6 -1.3331767 1 FALSE 6
> 7 -0.3055796 1 FALSE 7
> 8 1.3331767 1 FALSE 8
> 9 0.1574314 1 FALSE 9
> 10 -0.1574314 1 FALSE 10
> 11 -3.0958803 2 TRUE 1
> 12 12.4601615 2 TRUE 2
> 13 -5.2363532 2 TRUE 3
> 14 1.5419810 2 TRUE 4
> 15 7.7071005 2 TRUE 5
> 16 -0.3854953 2 FALSE 6
> 17 0.7673098 2 FALSE 7
> 18 2.9485984 2 FALSE 8
> 19 0.3854953 2 FALSE 9
> 20 -0.3716558 2 FALSE 10
> 21 -6.4139940 3 TRUE 1
> 22 -3.8162344 3 TRUE 2
> 23 -11.0518554 3 TRUE 3
> 24 2.7462631 3 TRUE 4
> 25 16.2543990 3 TRUE 5
> 26 -1.7353668 3 FALSE 6
> 27 1.3521369 3 FALSE 7
> 28 1.3521369 3 FALSE 8
> 29 0.2054067 3 FALSE 9
> 30 -1.7446691 3 FALSE 10
> 31 -6.7468356 4 TRUE 1
> 32 -11.3228243 4 TRUE 2
> 33 -18.0088554 4 TRUE 3
> 34 4.6264891 4 TRUE 4
> 35 9.2973991 4 TRUE 5
> 36 -4.1122576 4 FALSE 6
> 37 -0.5091994 4 FALSE 7
> 38 1.2787085 4 FALSE 8
> 39 -1.6867089 4 FALSE 9
> 40 -0.5091994 4 FALSE 10
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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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 and provide commented, minimal, self-contained, reproducible code. Received on Sun Oct 15 12:07:15 2006

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