CSC151 2010S, Class 41: Analyzing Procedures

Overview:
* HW 7
* Project Proposals
* Analyzing Procedures
  * Comparing algorithms.
  * Two related metrics: 
    Time and Procedure Calls.
  * Counting procedure calls by printing.
  * Tools for analysis.
* Lab!

Admin:
* We seem to have a number of ill students 
  today.  Please take extra precautions this 
  week. (Wash hands regularly, get enough 
  sleep, etc.)
* Preregistration is upon us!  Please talk to
  me about what CS course you should take next.

HW 7

; A bit of preparation for testing
(define world (image-show (image-new 200 200)))
(define yertle (turtle-new world))
(turtle-teleport! yertle 50 50)


(define koch-side!
  (lambda (turtle n side-length)
    (cond
      ((= n 0)
       (turtle-forward! turtle side-length))
      (else
       (koch-side! turtle (- n 1) (* side-length 2/3))
       (turtle-turn! turtle -60)
       (koch-side! turtle (- n 1) (/ side-length 3))
       (turtle-turn! turtle 120)
       (koch-side! turtle (- n 1) (/ side-length 3))
       (turtle-turn! turtle -60)))))

(define koch-snowflake!
  (lambda (turtle n side-length)
    (repeat 3
            (lambda ()
              (koch-side! turtle n side-length)
              (turtle-turn! turtle 120)))
    ))