title: Save a subplot in matplotlib
body: <p>Is it possible to save (to a png) an individual subplot in a matplotlib figure? Let's say I have</p>
  
  <pre><code>import pyplot.matplotlib as plt
  ax1 = plt.subplot(121)
  ax2 = plt.subplot(122)
  ax1.plot([1,2,3],[4,5,6])    
  ax2.plot([3,4,5],[7,8,9])
  </code></pre>
  
  <p>Is it possible to save each of the two subplots to different files or at least copy them separately to a new figure to save them?</p>
  
  <p>I am using version 1.0.0 of matplotlib on RHEL 5.</p>