(defun choose-distance-objects (dist)
  "choose-distant-objects: chooses the two longest away object thingies
   through ancient magic"
  (let ((o.b 0)
        (o.a 0)
        (vlist 0))    
    (dotimes (i 5) ;5 is suggested by Faloutsos & Lin
      (setf o.a (dist dist o.b))
      (setf o.b (dist dist o.a)))
    (setf vlist (list o.a o.b))))

(deftest test-ancillary()
  "Tests the ancillary functions necessary for the completion of fastmap and k-means."
  (combine-results
    (test-set-distance-matrix)
    (test-set-distance-matrix2)
    (test-choose-distance-objects)))

(deftest test-choose-distance-objects()
  (check
    (let ((x (choose-distance-objects
             (set-distance-matrix
              (make-array '(5 3) :initial-contents '((1 2 3)
                                                     (4 5 6)
                                                     (7 8 9)
                                                     (-500 -500 -500)
                                                     (500 500 500)))))))      
      (and (or (= (first x) 3) (= (first x) 4))
           (or (= (second x) 3) (= (second x) 4))))))
    
(deftest test-set-distance-matrix2()
  (check
    (let ((x (set-distance-matrix2
              (make-array '(2 2) :initial-contents '((0 0)
                                                     (0 1)))
              (make-array '(2 2) :initial-contents '((1 0)
                                                     (1 1)))))
          (z (make-array '(2 2) :initial-contents '((1 1.4142135)
                                                    (1.4142135 1)))))
      (equalp x z))))

(deftest test-set-distance-matrix()
  (check
    (let ((x (set-distance-matrix
              (make-array '(4 2) :initial-contents '((0 0)
                                                     (0 1)
                                                     (1 0)
                                                     (1 1)))))
          (z (make-array '(4 4) :initial-contents '((0 1 1 1.4142135)
                                                     (1 0 1.4142135 1)
                                                     (1 1.4142135 0 1)
                                                     (1.4142135 1 1 0)))))
      (equalp x z))))