anchor.diff: -;; Copyright © 2002 Donnie Cameron
  +;; Copyright © 2002-2018 Donnie Cameron
   ;;
   ;; ANN stands for Artificial Neural Network. This is a simple
   ;; implementation of the standard backpropagation neural network.
  
positive.code:          for x = (* (if (zerop (random 2)) 1 0) (random 1.0))
           for y = (* (if (zerop (random 2)) 1 0) (random 1.0))
           for c = (sqrt (+ (* x x) (* y y)))
           appending (list (list x y) (list (if (> c diameter) 0 1))))))
       
  
negative.code:              (incf correct)))
         finally (return (/ (truncate (* (/ correct total) 10000)) 100.0)))))
  
  (defun circle-training-points (count &key stats)
    (if stats
        (loop for a from 1 to count
           for x = (* (if (zerop (random 2)) 1 0) (random 1.0))
  