(I neglected to cc this to the list -- Bert)
On Sun, Sep 16, 2018 at 1:36 PM Bert Gunter <bgunter.4...@gmail.com> wrote: > You can do a mixed effects model using the existing id's without recoding. > > But if you insist, is this the sort of thing you want? > > set.seed(-12345) # for reprodicibility > > id <- factor(sample(2:5, 10, rep=TRUE)) > id > new.id <- factor(id,labels = seq_along(levels(id))) > new.id > > Note: There's a slightly slicker way to do this, but it bypasses the > factor() API, and I prefer not to do that. > > Cheers, > Bert > > > > > Bert Gunter > > "The trouble with having an open mind is that people keep coming along and > sticking things into it." > -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) > > > On Sun, Sep 16, 2018 at 12:52 PM Liu, Lei <lei....@wustl.edu> wrote: > >> Sorry for the confusion. I just want to recode the id variable to 1 to 5 >> in the bootstrapped sample. This way I can do e.g., a mixed effects model >> using the new id as the cluster. Thanks! >> >> Lei >> >> >> >> *From:* Bert Gunter [mailto:bgunter.4...@gmail.com] >> *Sent:* Sunday, September 16, 2018 2:21 PM >> *To:* Liu, Lei <lei....@wustl.edu> >> *Cc:* R-help <r-help@r-project.org> >> *Subject:* Re: [R] bootstrap sample for clustered data >> >> >> >> I can't make any sense of your post. Id 3 occurs 6 times, and 2 and 5 >> occur twice each in your example.. How do you get (1,1,2,2,3,3,4,4,5,5) out >> of that? In other words, specify the mapping of old id's to new. >> >> >> >> Bert >> >> >> Bert Gunter >> >> "The trouble with having an open mind is that people keep coming along >> and sticking things into it." >> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip ) >> >> >> >> >> >> On Sun, Sep 16, 2018 at 11:51 AM Liu, Lei <lei....@wustl.edu> wrote: >> >> Hi there, >> >> I tried to generate bootstrap samples for clustered data. Here is some >> code I found in the web to do the work: >> >> id=c(1, 1, 2, 2, 3, 3, 4, 4, 5, 5) >> y=c(.5, .6, .4, .3, .4, 1, .9, 1, .5, 2) >> x=c(0, 0, 1, 1, 0, 0, 1, 1, 1, 1 ) >> >> xx=data.frame(id, x, y) >> >> boot.cluster <- function(x, id){ >> >> boot.id <- sample(unique(id), replace=T) >> out <- lapply(boot.id, function(i) x[id%in%i,]) >> >> return( do.call("rbind",out) ) >> >> } >> >> boot.pro=boot.cluster(xx, xx$id) >> >> Now I have the output >> >> id x y >> 5 3 0 0.4 >> 6 3 0 1.0 >> 51 3 0 0.4 >> 61 3 0 1.0 >> 9 5 1 0.5 >> 10 5 1 2.0 >> 52 3 0 0.4 >> 62 3 0 1.0 >> 3 2 1 0.4 >> 4 2 1 0.3 >> >> However, the id variable is the original id, while I want to take the new >> id as (1, 1, 2, 2, 3, 3, 4, 4, 5, 5) for later analysis. Can anyone show me >> how to do it? Of note, the same original id may have duplicates since the >> bootstrap sample is drawn with replacement. Thanks a lot! >> >> Lei >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see >> 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. >> >> [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see 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.
