[R] Create a new var reflecting the order of subjects in existingvar

[Christos Hatzis]

Try this:

y <- rle(dat$ID)
unlist(sapply(y$lengths, FUN=function(x) seq(1,x)))

Christos Hatzis, Ph.D.
Nuvera Biosciences, Inc.
400 West Cummings Park
Suite 5350
Woburn, MA 01801
Tel: 781-938-3830
www.nuverabio.com
 
 

> -----Original Message-----
> From: r-help-bounces at stat.math.ethz.ch 
> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Nguyen 
> Dinh Nguyen
> Sent: Sunday, April 01, 2007 10:00 PM
> To: r-help at stat.math.ethz.ch
> Subject: [R] Create a new var reflecting the order of 
> subjects in existingvar
> 
> Dear R helpers
> I have a data set sth like this:
> set.seed(123);dat <- data.frame(ID= c(rep(1,2),rep(2,3), 
> rep(3,3), rep(4,4), rep(5,5)),
>                   var1 =rnorm(17, 35,2),
>                   var2=runif(17,0,1))
> dat
>    ID     var1       var2
> 1   1 33.87905 0.02461368
> 2   1 34.53965 0.47779597
> 3   2 38.11742 0.75845954
> 4   2 35.14102 0.21640794
> 5   2 35.25858 0.31818101
> 6   3 38.43013 0.23162579
> 7   3 35.92183 0.14280002
> 8   3 32.46988 0.41454634
> 9   4 33.62629 0.41372433
> 10  4 34.10868 0.36884545
> 11  4 37.44816 0.15244475
> 12  4 35.71963 0.13880606
> 13  5 35.80154 0.23303410
> 14  5 35.22137 0.46596245
> 15  5 33.88832 0.26597264
> 16  5 38.57383 0.85782772
> 17  5 35.99570 0.04583117
> I would like to create a new var in dat which reflects the 
> order of each subject (ID), like this
>    ID     var1       var2	 IDorder
> 1   1 33.87905 0.02461368       1
> 2   1 34.53965 0.47779597       2
> 3   2 38.11742 0.75845954       1
> 4   2 35.14102 0.21640794       2
> 5   2 35.25858 0.31818101       3
> 6   3 38.43013 0.23162579       1
> 7   3 35.92183 0.14280002       2
> 8   3 32.46988 0.41454634       3
> 9   4 33.62629 0.41372433       1
> 10  4 34.10868 0.36884545       2
> 11  4 37.44816 0.15244475       3
> 12  4 35.71963 0.13880606       4
> 13  5 35.80154 0.23303410       1
> 14  5 35.22137 0.46596245       2
> 15  5 33.88832 0.26597264       3
> 16  5 38.57383 0.85782772       4
> 17  5 35.99570 0.04583117       5
> 
> Thank you very much for your help
> Regards
> Nguyen
> 
>