[R] determine length of sequence of equal elements in a vector

[Jannis]

Dear list members,


I am seeking a function that returns me the length of a continous 
sequence of identical elements in a vector. Something like (or similar to):


example = c(1,1,1,2,2,3,3,3,3)


result = c(3,3,3,2,2,4,4,4,4)


I am quite sure there already exists a function to do this, I just cant 
figure out its name. Otherwise I would start programming my own function.



Best
Jannis