title: Python - axes and plt.figure()
body: <p>Could someone look at this code? I must do 3 sample of sinus axes.</p>
  
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  
  t = np.arange(0.0, 2.0, 0.01)
  fig = plt.figure()
  
  ax1 = fig.add_subplot(311)
  y1 = np.sin(2*np.pi*t)
  ax1.plot(t, y1);
  ax1.grid(True)
  ax1.set_ylabel('1 Hz');
  
  ax2 = fig.add_subplot(312)
  y2 = np.sin(4*np.pi*t)
  ax2.plot(t, y2);
  ax2.grid(True)
  ax2.set_ylabel('4 Hz');
  
  ax3 = fig.add_subplot(313)
  y3 = np.sin(6*np.pi*t)
  ax3.plot(t, y3);
  ax3.grid(True)
  ax3.set_ylabel('6 Hz');
  
  plt.show()
  </code></pre>
  
  <p>Could somebody say me why this code do nothing ? I only see "Figure 1" and that's all.</p>