title: in python pandas, how to save a 'grid chart'?
body: <p>i am quite new to pandas plot facilities, in the doc, the following command is really handy:</p>
  
  <pre><code>myplot = rts.ret.hist(bins=50, by=rts.primary_mic)
  </code></pre>
  
  <p>however, the problems comes when i try to get a figure reference from the plot and save it:</p>
  
  <pre><code>myfigure = myplot.get_figure()
  AttributeError: 'numpy.ndarray' object has no attribute 'get_figure'
  </code></pre>
  
  <p>what I understand is, rts.ret.hist(bins=50) returns a plot object, while rts.ret.hist(bins=50 returns an array object.</p>
  
  <p>how should I save my figure in this case?</p>
  
  <p>any clue?</p>
  
  <p>thanks!</p>