Hi, Here is another option if you already have a list you want to convert. This will handle different elements of the list being different lengths.
#Using your example data mydata <- list(c(1,2,3),c(4,5,6)) data.frame( OriginalListIndex = rep(x = seq_along(mydata), times = unlist(lapply(mydata, length))), Item = unlist(mydata) ) #Just to demonstrate that this method works generally mydata <- list(c(1,2,3), c(7,6), c(3,4,5,6,7,8,9)) data.frame( OriginalListIndex = rep(x = seq_along(mydata), times = unlist(lapply(mydata, length))), Item = unlist(mydata) ) HTH, Josh On Mon, Jul 26, 2010 at 7:46 AM, Johannes Graumann <johannes_graum...@web.de> wrote: > Hi, > > Any ideas on how to efficiently convert > >> list(c(1,2,3),c(4,5,6)) > > to > >> data.frame(OriginalListIndex=c(1,1,1,2,2,2),Item=c(1,2,3,4,5,6)) > > Thanks for any hints, > > Joh > > ______________________________________________ > 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. > -- Joshua Wiley Ph.D. Student, Health Psychology University of California, Los Angeles http://www.joshuawiley.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.