This assumes that for a particular id they all occur together in a run:
> cbind(start = which(!duplicated(id)), end = which(!duplicated(id, fromLast =
> TRUE)))
start end
[1,] 1 1
[2,] 2 3
[3,] 4 6
[4,] 7 7
[5,] 8 9
On Wed, May 26, 2010 at 12:14 AM, Robin Jeffries <rjeffr...@ucla.edu> wrote:
> 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.
