genetic-algorithm.ss

(define-library <genetic-algorithm>
  (import (scheme base) (only (srfi 27) random-real))
  (export climb fitness)
  (begin (define (fitness hill) (/ (apply + hill) (length hill)))
    (define (mutate parent percentage)
      (map (lambda (x) (+ x (modulo (random-real) (* x percentage))))
        parent))
    (define (climb fitness percentage parent)
      (let ([fitness-parent (fitness parent)])
        (if (> fitness-parent 0.9) parent
            (climb fitness percentage
              (let ([child (mutate parent percentage)])
                (if (> fitness-parent (fitness child)) parent child))))))))