# [plt-scheme] HtDP Exercise 23.4.1

2009-02-10 David Yrueta <dyrueta at gmail.com>:
>* [...]
*>* (define (integrate-kepler f left right)
*>* (local ((define (area-of-trap a b1 b2)
*>* (* a ( / ( + (f b1) (f b2)) 2)))
*>* (define midpoint ( / (+ right left) 2))
*>* (define alt-left (- midpoint left))
*>* (define alt-right (- right midpoint)))
*>* (+ (area-of-trap alt-left left midpoint)
*>* (area-of-trap alt-right midpoint right))))
*>* Am I in the ballpark?
*>* [...]
*
Hello David,
this implementation of the integration function looks good. As
Matthias said, thinking about some tests could help you convince
yourself that it is correct ;-)
For example, the procedure should yield exact results for any linear
function (ie. any function of the form (lambda (x) (+ a (* b x))) with
arbitrary real a and b)...
cu,
Thomas
--
When C++ is your hammer, every problem looks like your thumb.