;;; 3.3.scm
;;; 2024-08-31
;;; $Id: 3.3.scm 1.1 2024/10/27 09:49:37 s Exp $

(use gauche.sequence) ; for 'map-with-index' procedure
(define (main args)

; function 
  (define sum (^(x)   (fold + 0 x)))
  (define fix (^(x n) (/ (round (* x (expt 10 n))) (expt 10 n))))

; input
  (define r 0.08)
  (define istart 90)
  (define iend  101)
  (define n  (- iend istart))
  (define a  (list 90   91   92   93  94  95  96  97  98  99   100  101))
  (define x  (list 0    1e4  1e4  1e4 1e4 1e4 1e4 1e4 1e4 1e4  1e4  1e4))
  (define p  (list 0.07 0.08 0.09 0.1 0.1 0.1 0.1 0.1 0.1 0.07 0.05 0.04))
  (define pp (list 1    0    0    0   0   0   0   0   0   0    0    0))
  (define pv)
  (define sumofpv)

; calculating
  (define df (map-with-index (^(i _) (/ 1 (expt (+ 1 r) i))) a))
  (do((i 1 (+ i 1)))
     ((= i (+ n 1)) i)
     (set! (ref pp i) (- (ref pp (- i 1)) (ref p (- i 1)) ))
  )
  (set! pv (map (^(x y z) (* x y z)) pp x df))
  (set! sumofpv (sum pv))

  ; output
  (print "3.3.scm")
  (print "r " r)
  (print "istart " istart)
  (print "iend " iend)
  (print "n " n)
  (print "a " a)
  (print "x "  (map (^x (x->integer x))x))
  (print "p " p)
  (print "pp " (map (^x (fix x 2)) pp))
  (print "df " (map (^x (fix x 2)) df))
  (print "pv " (map (^x (x->integer x)) pv))
  (print "sum of pv " (x->integer sumofpv))
0)
;;; end