anchor.diff:      ?assertEqual(111412, round(latitudinal_width(60))),
       ?assertEqual(111694, round(latitudinal_width(90))).
   
  +
  +longitudinal_width_test() ->
  +    ?assertEqual(111319, round(longitudinal_width(0))),
  +    ?assertEqual(107550, round(longitudinal_width(15))),
  +    ?assertEqual(78847, round(longitudinal_width(45))),
  +    ?assertEqual(55800, round(longitudinal_width(60))),
  +    ?assertEqual(0, round(longitudinal_width(90))).
  +
   -endif.
  
positive.code:     111132.954 - 559.822 * math:cos(2.0 * LatRad) + 1.175 * math:cos(4.0 * LatRad).
  
  
  -ifdef(TEST).
  
  distance_test() ->
  
negative.code: 
  % Multiplier to convert degrees to radians
  -define(DEGREES_TO_RAD, 0.017453292519943295).
  
  % Constants
  -define(PI, 3.141592653589793).
  -define(E_SQ, 0.00669437999014).
  
  % Queries within a box, since the box is provided already, no adjustment
  % is necessary
  