; 5.12.scm
; 2024-10-12
; $Id: 5.12.scm 1.1 2024/11/02 12:04:55 s Exp $
;
; df : discount factor
; d  : dividend
; r  : interest rate
; g  : growth rate
; v  : value of the company

; function
(define sum (lambda (x) (fold + 0 x)))

; input
(define n  5)
(define r  0.15)
(define g1 0.1)
(define g2 0.05)
(define d0 10000)

; calculating
(define i  (iota n))
(define d1 (* d0 (+ 1 g1)))
(define df (map (lambda (x) (/ 1 (expt (+ 1 r) (+ x 1)))) i))
(define v5 (sum (map (lambda (x y) (* d1 x (expt (+ 1 g1) y))) df i)))
(define d5 (* d1 (expt (+ 1 g1) 4)))
(define v6 (/ (/ (* (+ 1 g2) d5) (- r g2)) (expt (+ 1 r) 5)))
(define v0 (+ v5 v6))

; output
(print '5.12.scm)
(print "r  " r )
(print "g1 " g1)
(print "g2 " g2)
(print "d0 " d0)
(print "d1 " (x->integer d1))
(print "df " (map (lambda (x) (/ (round (* x 1000)) 1000)) df))
(print "v5 " (x->integer v5))
(print "d5 " (x->integer d5))
(print "v6 " (x->integer v6))
(print "v0 " (x->integer v0))
; end