Re: [R] GLMM and data manipulation (2nd try)

From: Andrew Robinson <A.Robinson_at_ms.unimelb.edu.au>
Date: Sat, 03 May 2008 06:43:22 +1000

On Fri, May 02, 2008 at 03:06:31PM -0500, Giovanni Petris wrote:
>
> Hello,
>
> I posted a question yesterday but I got no replies, so I'll try to
> reformulate it in a more concise way.
>
> I have the following data, summarizing approval ratings on two
> different surveys for a random sample of 1600 individuals:
>
> > ## Example: Ratings of prime minister (Agresti, Table 12.1, p.494)
> > rating <- matrix(c(794, 86, 150, 570), 2, 2)
> > dimnames(rating) <- list(First = c("approve", "disapprove"),
> + Second = c("approve", "disapprove"))
> > rating
> Second
> First approve disapprove
> approve 794 150
> disapprove 86 570
>
> I would like to fit a logit model with approve/disapprove as response,
> survey (first/second) as a fixed effect, and subject as a random
> effect.
>
> 1) Is it possible to fit such a model directly using "lmer"?
>
> or
>
> 2) Should I unroll the table above into a dataframe containing also
> fictitious subject id's? If this is the case, what is a clean way
> of doing it?

Unroll it.

Asking for a "clean" way to do something is a disincentive because it implies that you know how to do it but not cleanly. In the future I would suggest that you do one of two things

  1. post your on dirty version and ask for a cleaner one, or
  2. just ask for something that works.

Something like ...

ratings <-

	data.frame(
	response = c(
		 rep(c(1,1), 794), 
		 rep(c(1,0), 150),
		 rep(c(0,1),  86),
		 rep(c(0,0), 570)),
	time = rep(c(1,2), 1600),
	subject=rep(1:1600, each=2))

test.lmer <- lmer(response ~ time + (1|subject), data=ratings,
     	     family=binomial)

but I don't know if you think that's clean or not.

Andrew  

> Thank you in advance,
> Giovanni Petris
>
> --
>
> Giovanni Petris <GPetris@uark.edu>
> Associate Professor
> Department of Mathematical Sciences
> University of Arkansas - Fayetteville, AR 72701
> Ph: (479) 575-6324, 575-8630 (fax)
> http://definetti.uark.edu/~gpetris/
>
> ______________________________________________
> 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.

-- 
Andrew Robinson  
Department of Mathematics and Statistics            Tel: +61-3-8344-6410
University of Melbourne, VIC 3010 Australia         Fax: +61-3-8344-4599
http://www.ms.unimelb.edu.au/~andrewpr
http://blogs.mbs.edu/fishing-in-the-bay/

______________________________________________
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.
Received on Fri 02 May 2008 - 20:53:17 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Fri 02 May 2008 - 22:30:36 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive