title: pandas show multiple bar graphs on a chart
body: <p>my data looks like this:</p>
  
  <pre><code>term    date    change1 change2
  aaa  2010-03-01   23.00   24.31
  bbb  2010-03-01   25.00   0.00
  ccc  2012-05-01   100.00  100.00
  </code></pre>
  
  <p>The date column can have repeated dates. I want to plot for each term, what the change1 and change2 is. I was thinking to have the term as the x-axis and change1 and change2 share the same y axis but be plotted as bar charts side by side. 
  I know how to do the y axis part but dont know how to set the x axis. I would also like each term to somehow show the date as well if possible otherwise this is not a priority.</p>
  
  <p>Heres what i have:</p>
  
  <pre><code>fig = plt.figure()
  ax = fig.add_subplot(111)
  ax2 = ax.twinx()
  df.change1.plot(kind = 'bar', color = 'red', ax = ax , position = 1)
  df.change2.plot(kind = 'bar', color = 'blue', ax = ax2, position = 2)
  ax.set_ylabel= ('change1')
  ax2.set_ylabel=('change2')
  plt.show()
  </code></pre>
  
  <p>Thanks,</p>