Here is another approach inspired by Jim's answer: > names(A1) <- paste0(seq_along(A1),'.') > tmp <- unlist(A1) > split( rep( seq_along(A1), sapply(A1,length) ), > as.numeric(sub('\\..+$','',tmp)) ) $`1` [1] 1
$`2` [1] 1 2 $`3` [1] 1 $`4` [1] 1 2 4 $`5` [1] 2 4 $`13` [1] 4 $`23` [1] 3 On Tue, Jul 8, 2014 at 11:10 AM, jim holtman <jholt...@gmail.com> wrote: > Try this: > >> A1<-list(c(1:4),c(2,4,5),23,c(4,5,13)) >> >> # unlist with the list number >> result <- do.call(rbind, sapply(seq(length(A1)), function(.indx){ > + cbind(value = A1[[.indx]], index = .indx) > + })) >> >> ans <- split(result[, 2], result[, 1]) >> ans > $`1` > [1] 1 > > $`2` > [1] 1 2 > > $`3` > [1] 1 > > $`4` > [1] 1 2 4 > > $`5` > [1] 2 4 > > $`13` > [1] 4 > > $`23` > [1] 3 > > > > Jim Holtman > Data Munger Guru > > What is the problem that you are trying to solve? > Tell me what you want to do, not how you want to do it. > > > On Tue, Jul 8, 2014 at 12:39 PM, Lorenzo Alfieri <alfio...@hotmail.com> > wrote: > >> Hi, >> I'm trying to find a way to reorder the elements of a list. >> Let's say I have a list like this: >> A1<-list(c(1:4),c(2,4,5),23,c(4,5,13)) >> >> > A1 >> [[1]] >> [1] 1 2 3 4 >> >> [[2]] >> [1] 2 4 5 >> >> [[3]] >> [1] 23 >> >> [[4]] >> [1] 4 5 13 >> >> All the elements included in it are values, while each sublist is a time >> index >> Now, I'd like to reorder the list (without looping) so to obtain one >> sublist for each value, which include all the time indices where each value >> appears. >> In other words, the result should look like this: >> >A2 >> [[1]] >> [1] 1 >> >> [[2]] >> [1] 1 2 #because value "2" appears in the time index [[1]] and [[2]] of >> A1 >> >> [[3]] >> [1] 1 >> >> [[4]] >> [1] 1 2 4 >> >> [[5]] >> [1] 2 4 >> >> [[13]] >> [1] 4 >> >> [[23]] >> [1] 3 >> >> Any suggestion? >> Thanks >> Alfio >> >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> 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. >> > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. -- Gregory (Greg) L. Snow Ph.D. 538...@gmail.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.