Vector addition of lists

Question

If I had a N lists each of length M, how could I write a nice clean function to return a single list of length M, where each element is the sum of the corresponding elements in the N lists?

(starting to learn lisp - go easy!)

Answer 1

This is a job for the map and apply functions. Here is a way to do it, with an EDIT suggested by Nathan Sanders:

(define (add-lists . more)
  (apply map + more))