old_contents: try:
  	import LightPipes
  except ImportError:
  	print "LightPipes not present"
  	exit()
  
  import matplotlib.pyplot as plt
  m=1
  nm=1e-9*m
  um=1e-6*m
  mm=1e-3*m
  cm=1e-2*m
  
  try:
  	LP=LightPipes.Init()
  
  	wavelength=20*um
  	size=30.0*mm
  	N=250
  
  	F=LP.Begin(size,wavelength,N)
  	F1=LP.CircAperture(0.15*mm, 0, -0.6*mm, F)
  	F2=LP.CircAperture(0.15*mm, 0, 0.6*mm, F)    
  	F=LP.BeamMix(F1,F2)
  	F=LP.Fresnel(0.0,F)
  	I=LP.Intensity(2,F)
  	plt.imshow(I); plt.axis('off');plt.title('intensity pattern')
  	plt.show()
  
  finally:
  	del LightPipes
  
new_contents: try:
  	import LightPipes
  except ImportError:
  	print "LightPipes not present"
  	exit()
  
  import matplotlib.pyplot as plt
  m=1
  nm=1e-9*m
  um=1e-6*m
  mm=1e-3*m
  cm=1e-2*m
  
  try:
  	LP=LightPipes.Init()
  
  	wavelength=20*um
  	size=30.0*mm
  	N=250
  
  	F=LP.Begin(size,wavelength,N)
  	F1=LP.CircAperture(0.15*mm, 0, -0.6*mm, F)
  	F2=LP.CircAperture(0.15*mm, 0, 0.6*mm, F)    
  	F=LP.BeamMix(F1,F2)
  	F=LP.Fresnel(50*cm,F)
  	I=LP.Intensity(2,F)
  	plt.imshow(I); plt.axis('off');plt.title('intensity pattern')
  	plt.show()
  
  finally:
  	del LightPipes
  
subject: Update Young.py