title: only 1 colorbar for multiple pie chart using matlibplot
body: <p>I have such a plot, and would like to add a the colorbar code (which color corresponds to what number) on the right hand below. I saw some example which where used for imshow not pie chart.</p>
  
  <pre><code>#!/usr/bin/env python
  """
  http://matplotlib.sf.net/matplotlib.pylab.html#-pie for the docstring.
  """
  from pylab import *
  
  fracs = [33,33,33]
  starting_angle = 90
  axis('equal')
  
  for item in range(9):
      color_vals = [-1, 0, 1]
      my_norm = matplotlib.colors.Normalize(-1, 1) # maps your data to the range [0, 1]
      my_cmap = matplotlib.cm.get_cmap('RdBu') # can pick your color map
  
      patches, texts, autotexts = pie(fracs, labels = None, autopct='%1.1f%%', startangle=90, colors=my_cmap(my_norm(color_vals)))
      subplot(3,3,item+1)
  
      fracs = [33,33,33]
      starting_angle = 90
      axis('equal')
      patches, texts, autotexts = pie(fracs, labels = None, autopct='%1.1f%%', startangle=90, colors=my_cmap(my_norm(color_vals)))
  
  
  for item in autotexts:
      item.set_text("")
  
  
  subplots_adjust(left=0.125, bottom=0.1, right=0.9, top=0.9, wspace=0.0, hspace=0.5)
  
  savefig('/home/superiois/Downloads/projectx3/GRAIL/pie1.png')
  show()
  </code></pre>
  
  <p>Also, it would be great if you tell me how to customize the size and location of colorbar code; Thanks.</p>