prob-mutation

[AM]

(defun prob-mutation (alist blist &key (factor 1) (prob-list nil))
    (loop for a in alist
          for b in blist
          for x in (if (null prob-list) 
                       (cumulative-sums (gen-repeat (length alist) (float (/ factor (length alist)))))
                     prob-list)
          when (probp x)
          collect b else collect a))

;;; with linear prob-incf
(prob-mutation (gen-repeat 100 1) (gen-repeat 100 2))
=> (1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 2 2 2 1 1 1 1 2 2 1 2 2 2 1 1 1 1 1 2 1 1 1 1 1 2 2 1 1 2 2 1 1 2 2 2 2 1 1 2 2 2 1 1 2 1 1 1 1 2 2 2 2 2 2 2 2 2 1 2 2 2 2 1 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2)

;;; with an external prob-list 0 to 1.0 to 0
(setf half-sine (filter-first 100 (gen-sine 200 1 1.0)))
(prob-mutation (gen-repeat 100 1) (gen-repeat 100 2) :prob-list half-sine)
=> (1 1 1 1 1 1 1 1 1 2 2 1 1 2 2 1 2 1 2 1 1 2 2 2 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 2 2 2 1 1 1 2 2 2 2 2 2 2 1 1 2 1 2 1 2 1 1 2 1 1 2 1 1 1 2 1 1)

;;; with an external prob-list 0 to 0.3 to 0
(setf half-sine (filter-first 100 (gen-sine 200 1 0.3)))
(prob-mutation (gen-repeat 100 1) (gen-repeat 100 2) :prob-list half-sine)
=> (1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 2 1 1 1 2 1 1 1 1 1 2 1 2 1 1 2 1 2 1 2 1 1 1 2 1 1 1 2 1 1 2 1 1 2 1 1 1 2 1 1 1 1 2 1 2 1 2 1 1 1 1 1 2 1 1 2 2 1 2 1 2 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1)