[R] find jumps in vector of repeats

[Berend Hasselman]

On 19-10-2013, at 02:17, "Benton, Paul" <hpaul.benton08 at imperial.ac.uk> wrote:

> Hello all,
> 
> I'm not really sure how to search for this in google/Rseek so there is probably a command to do it. I also know I could write an apply loop to find it but thought I would ask all you lovely R gurus. 
> 
> I have a very long vector (length=1855190) it looks something like this
> 
> 1111...2222...3333....etc so it would be something equivalent of doing:
> rep(c(1,2,3,4,5), c(10,30,24,65,3))
> 
> How can I find the index of where the step/jump is? For example using the above I would get an index of 0, 10, 40, 64, 129
> 
> Any help would be greatly appreciated.


z <- rep(c(1,2,3,4,5), c(10,30,24,65,3))
cumsum(rle(z)$lengths) 

Berend