On 25/10/15 11:28, John Sorkin wrote:
I have a file that has (1) Line numbers, (2) IDs. A given ID number can appear in more than one row. For each row with a repeated ID, I want to add a number that gives the sequence number of the repeated ID number. The R code below demonstrates what I want to have, without any attempt to produce the result, as I have no idea how to accomplish my goal.line <- c(1,2,3,4,5,6,7,8,9,10) ID<- c(1,1,2,3,4,5,6,7,8,8) cat("Note lines 1 and 2 both contain ID 1; lines 9 and 10 both contain ID 8") cbind(line,ID) Seq <- c(1,2,1,1,1,1,1,1,1,2) cat("Sequence numbers within ID added to the data") cbind(line,ID,Seq)
I *think* that unlist(lapply(rle(ID)$lengths,seq_len)) gives what you want. At least it does for the given example. cheers, Rolf Turner -- Technical Editor ANZJS Department of Statistics University of Auckland Phone: +64-9-373-7599 ext. 88276 ______________________________________________ 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.
