Wrong list. Post on r-sig-mixed-models. -- Bert
On Mon, Apr 23, 2012 at 8:46 PM, arun <smartpink...@yahoo.com> wrote: > Hi, > > I have some difficulty in figuring out whether I am doing correct or not. > > > A brief introduction about the work: It is a light/dark choice test > conducted in insect larvae. The response is binary (0- present in dark > area, 1-present in light area) and the experiment is run for 15 min, so > there are 15 repeated measurements per individual larva at 1 min > intervals. The factors which affect this study are Strain (2 levels-G > and S), wavelength of light (4 levels-blue, green, UV, red), and > starting response at 0 min (two levels- animal present in dark-D or > light-L). This is how I think it is nested. Strain nested inside > Wavelength, Subject (individual) nested within strain, Starting response > within subject, and time within Starting response. The data looks like this: > > Number Wavelength Strain Subject > Startingresponse time (min) > 1 Red G > 1 L 1 > 2 Red G > 1 L 2 > > --------------------------------------------------------------------------------------------------------------- > > --------------------------------------------------------------------------------------------------------------------- > 20 > Red G 1 > L 20 > 21 Red G > 2 D 1 > 22 Red G > 2 D 2 > > > --------------------------------------------------------------------------------------------------------------- > > > ----------------------------------------------------------------------------------------------------------------------- > > 40 Red G 2 > D 20 > > ----------------------------------------------------------------------------------------------------------------- > > ---------------------------------------------------------------------------------------------------------------- > > 121 Green G > 7 D 1 > 122 Green G 7 > D 2 > > ------------------------------------------------------------------------------------------------------------------------ > --------------------------------------------------------------------------------------------------------------------------- > > The model I used was: > > > (fm2 <-lmer(Response~Wavelength+Startingresponse+Strain+ time + > (time|Subject),family=binomial, data=Behavdat)) > > I am not sure how to specify the nested structures within the > model. > > Any help will be appreciated. > Thanks. > [[alternative HTML version deleted]] > > > ______________________________________________ > R-help@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. > -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ R-help@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.
