Dave: This is an attribute. So, you can get it as follows:
library(lme4) example(lmer) attr(VarCorr(fm1), "sc") > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of David Afshartous > Sent: Tuesday, February 05, 2008 2:37 PM > To: r-help@r-project.org > Subject: [R] Extracting level-1 variance from lmer() > > > All, > > How does one extract the level-1 variance from a model fit via lmer()? > > In the code below the level-2 variance component may be > obtained via subscripting, but what about the level-1 > variance, viz., the 3.215072 term? > (actually this term squared) Didn't see anything in the > archives on this. > > Cheers, > David > > > > > fm <- lmer( dv ~ time.num*drug + (1 | Patient.new), data=dat.new ) > > > VarCorr(fm) > $Patient.new > 1 x 1 Matrix of class "dpoMatrix" > (Intercept) > (Intercept) 8.519916 > > attr(,"sc") > scale > 3.215072 > > > VarCorr(fm)[[1]][1] > [1] 8.519916 > > VarCorr(fm)[[2]][1] > Error in VarCorr(fm)[[2]] : subscript out of bounds > > > > > > > > ########################################################## > set.seed(500) > n.timepoints <- 4 > n.subj.per.tx <- 20 > sd.d <- 5; > sd.p <- 2; > sd.res <- 1.3 > drug <- factor(rep(c("D", "P"), each = n.timepoints, times = > n.subj.per.tx)) > drug.baseline <- rep( c(0,5), each=n.timepoints, > times=n.subj.per.tx ) #Patient <- rep(1:(n.subj.per.tx*2), > each = n.timepoints) Patient.baseline <- rep( rnorm( > n.subj.per.tx*2, sd=c(sd.d, sd.p) ), each=n.timepoints ) > time.baseline <- > rep(1:n.timepoints,n.subj.per.tx*2)*as.numeric(drug=="D") > dv <- rnorm( n.subj.per.tx*n.timepoints*2, > mean=time.baseline+Patient.baseline+drug.baseline, sd=sd.res ) > > dat.new <- data.frame(drug, dv) > dat.new$Dind <- as.numeric(dat.new$drug == "D") dat.new$Pind > <- as.numeric(dat.new$drug == "P") dat.new$time.num = > rep(1:n.timepoints, n.subj.per.tx*2) dat.new$Patient.new = > rep(1:20, each=8) > > ______________________________________________ > 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. > ______________________________________________ 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.
