What package is the bootstrap() function from? There are many functions by that name....
My hunch is that it takes a vector at a time and puts it through dif.mns so that leads to the error in the apply() call but I can't verify. Michael On Mon, Feb 13, 2012 at 10:34 AM, hithit168 <ccchri...@live.com> wrote: > Thank you for your help, David. I was trying to run bootrapping on the > dataset "shoes" from MASS package. But I still have some problem here. > >> as.matrix(data.frame(shoes),nrows=10,ncols=2,byrow=T) > A B > [1,] 13.2 14.0 > [2,] 8.2 8.8 > [3,] 10.9 11.2 > [4,] 14.3 14.2 > [5,] 10.7 11.8 > [6,] 6.6 6.4 > [7,] 9.5 9.8 > [8,] 10.8 11.3 > [9,] 8.8 9.3 > [10,] 13.3 13.6 >> y=as.matrix(data.frame(shoes),nrows=10,ncols=2,byrow=T) >> class(y) > [1] "matrix" >> apply(y,1,diff) > [1] 0.8 0.6 0.3 -0.1 1.1 -0.2 0.3 0.5 0.5 0.3 >> dif.mns <- function(x2,tr1=.1,tr2=.2){ > + diffs=apply(x2,1,diff) > + mn1=mean(diffs) > + mn2=mean(diffs,tr=.1) > + mn3=mean(diffs,tr=.2) > + mn4=median(diffs) > + mns=c(mn1,mn2,mn3,mn4) > + list(mnds=round(mns,3))} >> dif.mns(y,tr1=.1,tr2=.2) > $mnds > [1] 0.410 0.400 0.417 0.400 > >> bootstrap(y,nboot=1000,theta=dif.mns) > Error in apply(x2, 1, diff) : dim(X) must have a positive length > > I am not sure what I am doing wrong. When I run apply(y,1,diff) I am able to > get output, and when I run dif.mns with just the original dataset, I am also > able to get output. > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Error-in-apply-x2-1-diff-dim-X-must-have-a-positive-length-tp4382435p4384129.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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.