You can also try ?rep and something like
dat <- read.table(textConnection("ID record
1 20
. 30
. 25
2 26
. 15
3 21
"),header=TRUE,na.strings=".")
ind <- !is.na(dat$ID)
id <- dat$ID[ind]
reps <- diff(c(seq_len(nrow(dat))[ind],nrow(dat)+1))
dat$new.id <- rep(id,reps)
dat
ID record new.id
1 1 20 1
2 NA 30 1
3 NA 25 1
4 2 26 2
5 NA 15 2
6 3 21 3
> -----Original Message-----
> From: r-help-boun...@r-project.org
> [mailto:r-help-boun...@r-project.org] On Behalf Of Zhixin Liu
> Sent: Sunday, December 14, 2008 7:57 PM
> To: r-help@r-project.org
> Subject: [R] how to create duplicated ID in multi-records per
> subject dataset
>
> Hi R helpers,
>
> If I have a dataset looks like:
> ID record
> 1 20
> . 30
> . 25
> 2 26
> . 15
> 3 21
> 4.....................
>
> And I want it becomes
> ID record
> 1 20
> 1 30
> 1 25
> 2 26
> 2 15
> 3 21
> 4.....................
>
> That is, I have to duplicate IDs for those with multiple
> records. I am wondering it is possible to be done in R, and I
> am grateful if you would like to show me the direction.
>
> Many thanks!
>
> Zhixin
>
> ______________________________________________
> 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.
>
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
