R help - Oct 2011 - question R regarding consecutive numbers

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?

 

Thanks, S.B.


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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