Hello all,

is there a function in Opusmodus similar to this one?

Best, Achim

(defun x-dx (ls)

" Returns the list of the intervals between 
the consecutive values of a list <ls>. 
<ls> can also be a list of lists. 

Examples: 
(x-dx '(0 340 450 600 500 123)) => (340 110 150 -100 -377)
(x-dx '((0 340 450 600 500 123) (30 200 350 500 450 200 600)))
=> ((340 110 150 -100 -377) (170 150 150 -50 -250 400))"

  (labels ((x-dx-fun (lst)
             (loop for i in lst
                   for j in (cdr lst)
                   collect (- j i))))
    (if (numberp (first ls))
        (x-dx-fun ls)
      (mapcar #'x-dx-fun ls))))

(difference '(0 340 450 600 500 123))
(mapcar 'difference '((0 340 450 600 500 123) (30 200 350 500 450 200 600)))

Thanks. Could not find it.