title: How to show matplotlib plots?
body: <p>I am sure the configuration of <code>matplotlib</code> for python is correct since I have used it to plot some figures.</p>
  <p>But today it just stop working for some reason. I tested it with really simple code like:</p>
  <pre><code>import matplotlib.pyplot as plt
  import numpy as np
  x = np.arange(0, 5, 0.1)
  y = np.sin(x)
  plt.plot(x, y)
  </code></pre>
  <p>There's no error but just no figure shown up.</p>
  <p>I am using python 2.6, Eclipse in Ubuntu</p>