SICP Exercise 2.44: Splitting Up

Define the procedure up-split used by corner-split. It is similar to right-split, except that it switches the roles of below and beside.

up-split is very similar... Here's right-split:

(define (right-split painter n)
  (if (= n 0)
      painter
      (let ((smaller (right-split painter (- n 1))))
        (beside painter (below smaller smaller)))))

To produce up-split we simply rename the procedure and recursive call and switch below and beside around to give:

(define (up-split painter n)
  (if (= n 0)
      painter
      (let ((smaller (up-split painter (- n 1))))
        (below painter (beside smaller smaller)))))

Using the spiral we produced earlier we can put this to the test:

((up-split spiral 3) window)

...produces the following: