;;Binomial variable generator
;;output:Nil or T (failure or success respectively)

;(load "globals")

(defun randbin1 (p)
            (if (< (my-random 1.0) p)
                t
                nil))
    
(defun rand_p ()
     (setf a 16807)
     (setf m 2147483647)
     (setf q 127773)
     (setf r 2836)
     (setf x (my-random 100000.0))
     (setf x_new  (- (* a (mod x q)) (* r (/ x q))))
     (if (> x_new 0) (setf x x_new) (setf x (+ x_new m)))
     (values (/ x m)))


;;Normal variable generator using Box-Muller Method
;;input mean and standard deivation
;;output a random normal number


(defmacro while (test &rest body)
     `(do ()
         ((not ,test))
        ,@body))



(defun randnorm (mu sigma)
	   (setf s 1)
	   (while (>= s 1)
	     (let* ((u1 (my-random 1.0))
		    (u2 (my-random 1.0)))
		  (setf v1 (- (* 2 u1) 1))
		  (setf v2 (- (* 2 u2) 1))
		  (setf s (+ (* v1 v1) (* v2 v2)))))
	   (setf x (* v1 (/ (isqrt (round (* (/ (* -2 (log s)) s) 100))) 10)))
	   (setf norm (+ mu (* sigma x)))
	   (values norm))



(defun first0 (lst)
  (<= (car lst) ))


;;cumulative sum of cost and value
(defun current_cum_value (list)
  (let* ((v 0))
    (dolist (i list)
      (setf v (+ v (car i))))
    v))

(defun current_cum_cost (list)
  (let* ((c 0))
    (dolist (i list)
      (setf c (+ c (nth 1 i))))
    c))

(defun cumsum_vc (current_value current_cost)
  (setf cum_value (+ cum_value current_value))
  (setf cum_cost (+ cum_cost current_cost)))