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<mailto: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<http://boot.id> <- sample(unique(id), replace=T) out <- lapply(boot.id<http://boot.id>, function(i) x[id%in%i,]) return( do.call("rbind",out) ) } boot.pro<http://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<mailto: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.
