Вывести график тригонометрической функции COS() — QBasic(Бейсик)

CONST Pi = 3.14159265358#
SCREEN 12
  '  Параметры
  r = 100
  oy = r
  '  Сетка
  LINE (0, 240)-(640, 240), 8
  FOR x = 0 TO Pi * 2 STEP Pi / 4
   LINE (x * r, 230)-(x * r, 250), 8
  NEXT
  '  График
  FOR x = 0 TO Pi * 2 STEP Pi / 360
   ny = COS(x) * r: nx = x * r
   LINE (ox, 240 - oy)-(nx, 240 - ny), 10
   ox = nx: oy = ny
  NEXT