Hi Marianne, How about this...
ac.ad <- unstack(dat1, choice ~ cond1:cond2)[, c("A.C", "A.D")] acad.xtab <- with(ac.ad, table(A.C, A.D)) Michael On 29 November 2010 20:18, Marianne Promberger <marianne.promber...@kcl.ac.uk> wrote: > Dear list, > > I have data like this: > > dat1 <- data.frame(subject=rep(1:10,2), > cond1=rep(c("A","B"),each=5), > cond2=rep(c("C","D"),each=10), > choice=sample(0:1,10,replace=TRUE)) > > I would like to compare subjects' "choice" for (cond1=="A" & > cond2=="C") vs (cond1=="A" & cond2=="D"), using mcnemar.test > > The ?mcnemar.test example has the data in a matrix: > > Performance > 2nd Survey > 1st Survey Approve Disapprove > Approve 794 150 > Disapprove 86 570 > > > So for my case, I need something like: > > Choice > AC > AD 0 1 > 0 ... > 1 > > Where "..." would be the sum of subjects who answered 0 or 1 to AC > and/or AD respectively. > > I can get the first step by making an extra variable: > > dat1$condnew <- paste(dat1$cond1,dat1$cond2,sep="") > > although I am sure there are more elegant ways, and especially, I am > stumped how to fill in the cells of the table. > > Thanks, > > Marianne > > -- > Marianne Promberger PhD, King's College London > http://promberger.info > R version 2.12.0 (2010-10-15) > Ubuntu 9.04 > > ______________________________________________ > 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.