1 665c255d 2023-08-04 jrmu ;; Exercise 1.30.  The sum procedure above generates a linear recursion. The procedure can be rewritten so that the sum is performed iteratively. Show how to do this by filling in the missing expressions in the following definition:
 2 665c255d 2023-08-04 jrmu 
 3 665c255d 2023-08-04 jrmu (define (sum term a next b)
 4 665c255d 2023-08-04 jrmu   (define (iter a result)
 5 665c255d 2023-08-04 jrmu     (if (> a b)
 6 665c255d 2023-08-04 jrmu 	result
 7 665c255d 2023-08-04 jrmu 	(iter (next a) (+ (term a) result))))
 8 665c255d 2023-08-04 jrmu   (iter a 0))
 9 665c255d 2023-08-04 jrmu 
10 665c255d 2023-08-04 jrmu (define (integral f a b dx)
11 665c255d 2023-08-04 jrmu   (define (add-dx x) (+ x dx))
12 665c255d 2023-08-04 jrmu   (* (sum f (+ a (/ dx 2.0)) add-dx b)
13 665c255d 2023-08-04 jrmu      dx))
14 665c255d 2023-08-04 jrmu 
15 665c255d 2023-08-04 jrmu (define (cube x) (* x x x))
16 665c255d 2023-08-04 jrmu 
17 665c255d 2023-08-04 jrmu (define (test-case actual expected)
18 665c255d 2023-08-04 jrmu   (load-option 'format)
19 665c255d 2023-08-04 jrmu   (newline)
20 665c255d 2023-08-04 jrmu   (format #t "Actual: ~A Expected: ~A" actual expected))
21 665c255d 2023-08-04 jrmu 
22 665c255d 2023-08-04 jrmu 
23 665c255d 2023-08-04 jrmu 
24 665c255d 2023-08-04 jrmu (test-case (integral cube 0.0 1.0 0.001) 0.25)