new_contents: #%matplotlib inline  # for IPython notebook
  
  import numpy as np
  import matplotlib.pyplot as plt
  
  w=np.linspace(-10, 10, 100)
  a = np.ones((1,100),float)
  
  nom = 1j*w+a[0]
  denom =1j*w+2*a[0]
  h=nom/denom
  
  ang = np.angle(h, deg=True)
  
  #for debug
  #print(w)
  #print(nom)
  #print(denom)
  #print(h)
  #print(ang)
  
  plt.figure()
  plt.plot(w,ang)
  
subject: Create s+1_s+2.py