w = 320
h = 320
dim canvas(w,h)
for pts = 1 to 1000
  x = (rnd(1) * 31) - 15
  y = (rnd(1) * 31) - 15
  r = x * x + y * y
  if (r > 100) and (r < 225) then
    x = int(x * 10 + w/2)
    y = int(y * 10 + h/2)
    canvas(x,y) = 1
  end if
next pts

' -----------------------------
' display the graphic
' -----------------------------
graphic #g, w,h
for x = 1 to w
  for y = 1 to h
     if canvas(x,y) = 1 then  #g "color green ; set "; x; " "; y else #g "color blue ; set "; x; " "; y
  next y
next x
render #g
#g "flush"