Haskell group descripted there: http://www.haskell.org/ghc/docs/latest/html/libraries/base/Data-List.html#v:group

example :

group "Mississippi" = ["M","i","ss","i","ss","i","pp","i"]

Is there simple F# way of doing it?

I can implement something alike

let rec sameCounter (data : list<float>) el same (ss : list<float * int>) = 
    if data.Length > (el + 1) then
        if data.[el] = data.[el + 1] then
                              sameCounter data (el + 1) <| same + 1  <| ss
        else if same > 0 then sameCounter data (el + 1) <| 0         <| (data.[el], same) :: ss
             else             sameCounter data (el + 1) <| 0         <| ss
    else ss
let group d = sameCounter d 0 0 []

but it's a bit ugly way I think, is there better variant?