[R] replace id by running number

[Phil Spector]

The rle (run length encoding) function is ideal for
problems like this:

> y <- c(4,4,4,2,45,12,12)
> rr = rle(y)
> rep(seq(along=rr$values),rr$lengths)
[1] 1 1 1 2 3 4 4


 					- Phil Spector
 					 Statistical Computing Facility
 					 Department of Statistics
 					 UC Berkeley
 					 spector at stat.berkeley.edu


On Sat, 27 Mar 2010, sun wrote:

> Dear all,
>
> I want to replace an (unsorted) id variable in a large dataset by a running
> number without changing the order of the cases.
>
> E.g.,
>
> y <- c(4,4,4,2,45,12,12)
>
> should be replaced by something like
>
> x <- c(1,1,1,2,3,4,4)
>
> Sorry for this simple question  & thank you very much for your help!
>
>
>
>
>
>
> 	[[alternative HTML version deleted]]
>
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