(*  CS 2SC3 / SE 2S03
 *  Assignment 1 Solution
 *
 *  Author: W. M. Farmer
 *  Revised: October 6, 2009
 *
 *)

let direction (x,y) = 
  if x = 0. && y < 0. then "south"
  else if x = 0. && y > 0. then "north"
  else if x < 0. && y = 0. then "west"
  else if x > 0. && y = 0. then "east"
  else if x < 0. && y < 0. then "southwest"
  else if x < 0. && y > 0. then "northwest"
  else if x > 0. && y < 0. then "southeast"
  else if x > 0. && y > 0. then "northeast" 
  else "no direction" ;; 

let test_direction (x,y) =
  let x_string = string_of_float x in
  let y_string = string_of_float y in
  let output_string = direction (x,y) in
  print_string 
    ("When direction is applied to " ^ "(" ^ x_string ^ "," ^ y_string ^ 
     "), the output is " ^ "\"" ^ output_string ^ "\".\n") ;;

test_direction (0.,-0.4) ;;
test_direction (0.,6.6) ;;
test_direction (-4.,0.) ;;
test_direction (23.6,0.) ;;
test_direction (-0.677,-56.) ;;
test_direction (-1000000.,79.9) ;;
test_direction (0.00009,-0.00007) ;;
test_direction (4.4,0.23) ;;
test_direction (0.,0.) ;;