Re: [R] sequence number for 'long format'

2009-05-01 Thread William Dunlap
> -Original Message- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of David Freedman > Sent: Friday, May 01, 2009 11:52 AM > To: r-help@r-project.org > Subject: [R] sequence number for 'long format' > > > D

Re: [R] sequence number for 'long format'

2009-05-01 Thread Gabor Grothendieck
Try this: ds$seq <- ave(ds$id, ds$id, FUN = seq_along) On Fri, May 1, 2009 at 2:52 PM, David Freedman <3.14da...@gmail.com> wrote: > > Dear R-help list, > > I've got a data set in long format - each subject can have several (varying > in number) measurements, with each record representing one me

[R] sequence number for 'long format'

2009-05-01 Thread David Freedman
Dear R-help list, I've got a data set in long format - each subject can have several (varying in number) measurements, with each record representing one measurement. I want to assign a sequence number to each measurement, starting at 1 for a person's first measurement. I can do this with the by