Re: running sum of counts

[Sundar Dorai-Raj <sundar.dorai-raj@PDF.COM>]

Tim Wade wrote:

> Hello:
>
> I have what I'm sure is a very simple question.
>
> I have a vector like this:
>
> 1 1 1 1 2 2 2 3 3 4 4 4 4 4 5 5 5 5 5 6 7 3 3 3 2 2.
>
> I would like to generate a sequence consisting of a
> running sum of count values, like this:
>
> 1 2 3 4 1 2 3 1 2 1 2 3 4 5 1 2 3 4 5 1 1 1 2 3 1 1.
>
> Thanks very much for any assistance!
>
> Tim
Hi Tim,

I'm assuming the last number in the second sequence should really be a 2 
and not a one. My solution isn't pretty, but it does the job:
> x
 [1] 1 1 1 1 2 2 2 3 3 4 4 4 4 4 5 5 5 5 5 6 7 3 3 3 2 2
> unlist(sapply(diff(c(0, which(diff(c(x, Inf)) != 0))), seq))
 [1] 1 2 3 4 1 2 3 1 2 1 2 3 4 5 1 2 3 4 5 1 1 1 2 3 1 2

--sundar