/* debugmode(true);  */
/* have not figured how to include another file */

add(c,a,b) := (
  put(c, get(a, 'x) + get(b, 'x), 'x),
  put(c, get(a, 'y) + get(b, 'y), 'y),
  put(c, get(a, 'z) + get(b, 'z), 'z)
);

subtract(c,a,b) := (
  put(c, get(a, 'x) - get(b, 'x), 'x),
  put(c, get(a, 'y) - get(b, 'y), 'y),
  put(c, get(a, 'z) - get(b, 'z), 'z)
);

dot(a,b) := (
  get(a, 'x) * get(b, 'x)
  +   get(a, 'y) * get(b, 'y)
  + get(a, 'z) * get(b, 'z)
);

magnitude(a) := (
  sqrt(dot(a,a))
);

direction_r(a) := (
  atan2(get(a, 'y), get(a, 'x))
);

direction_d(a) := (
  atan2(get(a, 'y), get(a, 'x)) * 90.0 / asin(1.0)
);

cross(c,a,b) := (
  put(c, get(a, 'y) * get(b, 'z) - get(b, 'y) * get(a, 'z), 'x),
  put(c, -( get(a, 'x) * get(b, 'z) - get(b, 'x) * get(a, 'z)), 'y),
  put(c, get(a, 'x) * get(b, 'y) - get(b, 'x) * get(a, 'y), 'z)
);


print_vector( a ) := (
  print( a, " = ", get( a, 'x ), "i + ", get( a, 'y ),"j + ", get( a, 'z ), "k")
  ); 


main() := (
  /* declare local variables */
/*  block(modedeclare[my_height_feet, my_height_meters],float), */
  put(a, 4.0, 'x), 
  put(a, -3.0, 'y), 
  put(a, 0.0, 'z), 
  
  put(b, 6.0, 'x), 
  put(b, 8.0, 'y), 
  put(b, 0.0, 'z), 
  
  get(a, 'x),
  get(a, 'y),
  get(a, 'z),
  get(b, 'x),
  get(b, 'y),
  get(b, 'z),
  add(c,a,b),
  subtract(d,b,a),
  subtract(e,a,b),

  put(f, 2.0, 'x), 
  put(f, -3.0, 'y), 
  put(f, 7.0, 'z), 
  
  put(g, 12.0, 'x), 
  put(g, 45.0, 'y), 
  put(g, -8.0, 'z), 
  
  put(h, -5.0, 'x), 
  put(h, -3.0, 'y), 
  put(h, 42.0, 'z), 

  print_vector(a),
  print_vector(b),
  print_vector(c),
  print_vector(d),
  print_vector(e),
  print_vector(f),
  print_vector(g),
  print_vector(h),
  print("magnitude of a = ",magnitude(a)),
  print("magnitude of b = ",magnitude(b)),
  print("magnitude of c = ",magnitude(c)),
  print("magnitude of d = ",magnitude(d)),
  print("magnitude of e = ",magnitude(e)),
  print("direction of a in radians = ", direction_r(a)),
  print("direction of b in radians = ", direction_r(b)),
  print("direction of c in radians = ", direction_r(c)),
  print("direction of d in radians = ", direction_r(d)),
  print("direction of e in radians = ", direction_r(e)),
  print("direction of a in degrees = ", direction_d(a)),
  print("direction of b in degrees = ", direction_d(b)),
  print("direction of c in degrees = ", direction_d(c)),
  print("direction of d in degrees = ", direction_d(d)),
  print("direction of e in degrees = ", direction_d(e)),
  print("a dot a = ",dot(a,a)),
  print("a dot b = ",dot(a,b)),
  print("b dot a = ",dot(b,a)),
  print("a dot c = ",dot(a,c)),
  print("d dot a = ",dot(d,a)),
  print("a dot e = ",dot(a,e)),
  print("e dot a = ",dot(e,a)),
  cross(aca,a,a),
  cross(acb,a,b),
  cross(bca,b,a),
  cross(acc,a,c),
  cross(dca,d,a),
  cross(ace,a,e),
  cross(eca,e,a),

  cross(fcg,f,g),
  cross(fch,f,h),
  cross(gch,g,h),
  cross(gcf,g,f),
  cross(hcf,h,f),
  cross(hcg,h,g),

  print_vector(aca),
  print_vector(acb),
  print_vector(bca),
  print_vector(acc),
  print_vector(dca),
  print_vector(ace),
  print_vector(eca),

  print_vector(fcg),
  print_vector(fch),
  print_vector(gch),
  print_vector(gcf),
  print_vector(hcf),
  print_vector(hcg)
  
);

main();