! demo1.zpl
!
numsteps = 10
FOR i = 0, numsteps, 1
	py = i / numsteps
	RAYTRACE 0, 0, 0, py, 1
	yf = RAYY(NSUR())
	RAYTRACE 0, 0, 0, py, 3
	yc = RAYY(NSUR())
	Print "Pupil zone = ", py, " ZTCA = ", yf - yc
NEXT
