# to operate this progam, copy it to your own directory (as "box.sm"),
	# start sm, 
	#      (start a plot window if there is't one already with device x11).
	# while in sm, type:  input box.sm
	#
	define N 10000
	#  "random" gives random numbers uniformly distributed between 0 and 1.
	#  x & y below each are randomly distributed between -1 and +1.
	set x=2*random($N)-1
	set y=2*random($N)-1
	set t= x*x+y*y < 1 ? 1 : 0
	limits -1 1 -1 1
	box 3 3 3 3
	ctype red
	ltype 2
	circle 0 0 1
	ctype 0
	
	ltype 0
        expand .5
	ptype 20 3
	points x y
        ctype red
	points x y if(x*x+y*y<1)
	ctype 0