[R] question R regarding consecutive numbers

[Duncan Murdoch]

On 27/10/2011 8:43 AM, Samir Benzerfa wrote:
> Hi  everyone
>
>
>
> Do you know about any possibility in R to check for consecutive numbers in
> vectors? That is, I do not only want to count the number of observations in
> total (which can be done table(x)), but I also want to count for instance
> how many times that vector contains a certain number consecutively.
>
>
>
> For example in the following vector x the number "1" appears 7 times.
> However, I want to check for instance how many times two consecutive 1's
> appear in the vector, which would actually be two times the case in the
> below vector.
>
>
>
> >  x=c(1,1,3,4,9,1,9,1,5,4,5,2,1,1,1,6)
>
>
>
> Any ideas for this issue?

How about this?

 > runs <- rle(x)
 > with(runs, table(values, lengths))
       lengths
values 1 2 3
      1 2 1 1
      2 1 0 0
      3 1 0 0
      4 2 0 0
      5 2 0 0
      6 1 0 0
      9 2 0 0

Duncan