;; Unicalc test cases

;; Function close-enough is meant to test whether two inexact quantites
;; have a relative difference that is within the specified tolerance.

;; This is used in cases where answers might not match exactly.

(reset-tests)

(define tolerance 1e-6)

(define (relative-error x y)
  (cond ((= x y) 0)
        ((not (= x 0)) (/ (abs (- x y)) x))
        (else (/ (abs (- x y)) y))))

(define (close-enough Quantity1 Quantity2)
  (and (equal? (list (get-num Quantity1) (get-den Quantity1))
               (list (get-num Quantity2) (get-den Quantity2)))
       (< (relative-error (get-quant Quantity1) (get-quant Quantity2) ) tolerance)))


(check-expect (close-enough
       (normalize-unit 'second) 
       (make-QL 1.0 '(second) '())) #t)

(check-expect (close-enough
       (normalize-unit 'gram) 
       (make-QL 0.001 '(kg) '())) #t)

(check-expect (close-enough
       (normalize-unit 'kilometer) 
       (make-QL 1000.0 '(meter) '())) #t)

(check-expect (close-enough 
       (normalize-unit 'day) 
       (make-QL 86400.0 '(second) '())) #t)

(check-expect (close-enough
       (normalize-unit 'newton) 
       (make-QL 1.0 '(kg meter) '(second second))) #t)


(check-expect (close-enough 
       (normalize 
        (make-QL 1.0 '(mile) '(hour))) 
        (make-QL 0.44704 '(meter) '(second))) #t)

(check-expect (close-enough 
       (normalize 
        (make-QL 1e6 '(pound) '(mile mile))) 
        (make-QL 0.1751329931553838 '(kg) '(meter meter))) #t)

(check-expect (close-enough 
       (normalize (make-QL 1.0 '(newton meter) '(second))) 
       (make-QL 1.0 '(kg meter meter) '(second second second))) #t)

(check-expect (close-enough
       (normalize (make-QL 1.0 '(volt) '())) 
       (make-QL 1.0 '(kg meter meter) '(ampere second second second))) #t)

(check-expect (close-enough 
       (multiply (normalize (make-QL 1 '(foot) '())) (normalize (make-QL 1.0 '(acre) '()))) 
       (make-QL 1233.481837547520 '(meter meter meter) '())) #t)

(check-expect (close-enough
      (multiply (make-QL 1.0 '() '()) (make-QL 1.0 '(kg meter) '(second))) 
      (make-QL 1.0 '(kg meter) '(second))) #t)

(check-expect (close-enough
     (multiply (make-QL 1.0 '(chicken) '(meter meter)) 
               (make-QL 100.0 '(meter meter) '()))
     (make-QL 100.0 '(chicken) '())) #t)

(check-expect (close-enough (multiply (normalize (make-QL 100 '(tadpole) '(gallon))) 
                              (make-QL 1.0 '(meter meter meter) '())) 
                    (make-QL 26417.20523581484153781299 '(tadpole) '())) #t)


(check-expect (close-enough
      (divide (normalize (make-QL 1.0 '(yard) '())) 
              (normalize (make-QL 1.0 '(foot) '()))) 
      (make-QL 3.0 '() '())) #t)

(check-expect (close-enough
      (divide (normalize (make-QL 1.0 '(mile) '())) 
              (normalize (make-QL 1.0 '(foot) '()))) 
      (make-QL 5280.0 '() '())) #t)

(check-expect (close-enough (divide (normalize (make-QL 1.0 '(torr) '())) (normalize (make-QL 1.0 '(atmosphere) '()))) 
                    (make-QL 0.0013157894736842105 '() '())) #t)


(check-expect (close-enough 
      (add (make-QL 1.0 '(meter) '()) 
           (make-QL 1.0 '(meter) '())) 
      (make-QL 2.0 '(meter) '())) #t)

(check-expect (close-enough (add (normalize (make-QL 1.0 '(foot) '())) (normalize (make-QL 1.0 '(meter) '()))) 
                    (make-QL 1.3048 '(meter) '())) #t)

(check-expect (close-enough (add (normalize (make-QL 1 '(meter) '())) (normalize (make-QL 1.0 '(foot) '()))) 
                    (make-QL 1.3048 '(meter) '())) #t)


(check-expect (close-enough 
      (subtract (make-QL 1.0 '(meter) '()) (make-QL 1.0 '(meter) '())) 
      (make-QL 0.0 '(meter) '())) #t)

(check-expect (close-enough (subtract (normalize (make-QL 1.0 '(foot) '())) (normalize (make-QL 1.0 '(meter) '()))) 
                    (make-QL -0.6952 '(meter) '())) #t)

(check-expect (close-enough (subtract (normalize (make-QL 1.0 '(meter) '())) (normalize (make-QL 1.0 '(foot) '()))) 
                    (make-QL 0.6952 '(meter) '())) #t)

(check-expect (close-enough (power (normalize (make-QL 3.0 '(foot) '(second))) 2)
                    (make-QL 0.83612736 '(meter meter) '(second second))) #t)

(check-expect (close-enough 
      (power (normalize (make-QL 42.0 '(meter) '(second))) 0)
      (make-QL 1.0 '() '())) #t)

(check-expect (close-enough
      (power (normalize (make-QL 2.0 '() '(second))) -1) 
      (make-QL 0.5 '(second) '())) #t)

(generate-report)