Tena koe Robin See rle - it doesn't do exactly what you want but by looking at the code (simply enter rle without brackets) you should be able to get there.
HTH ... Peter Alspach > -----Original Message----- > From: r-help-boun...@r-project.org [mailto:r-help-boun...@r- > project.org] On Behalf Of Robin Jeffries > Sent: Wednesday, 26 May 2010 4:15 p.m. > To: r-help@r-project.org > Subject: [R] Counting indexes > > Hallo! > > I have a vector of ID's like so, > id <- c(1,2,2,3,3,3,4,5,5) > > I would like to create a [start,stop] pair of vectors that index the > first > and last observation per ID. > > For the ID list above, it would look like > 1 1 > 2 3 > 4 6 > 7 7 > 8 9 > > I haven't worked with indexes/data manipulation much in R, so any > pointers > would be helpful. > > Many thanks! > > ~~~~~~~~~~~~~~~~~~~ > -Robin Jeffries > Dr.P.H. Candidate in Biostatistics > UCLA School of Public Health > rjeffr...@ucla.edu > 530-624-0428 > > [[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. ______________________________________________ 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.
