title: Exact Subfigure sizing in matplotlib
body: <p>I'm plotting some indices data on A4 paper with 6 images in 3x2 row-cols.  I've got the basic code working and it plots this dataframe data into the following 6 plots.</p>
  
  <p><a href="http://imgur.com/frNjth3" rel="nofollow">http://imgur.com/frNjth3</a></p>
  
  <pre><code>def plot_idx(df,image,key):
      # reset the default parameters
      plt.rcParams['font.size'] = 8.
      plt.rcParams['figure.figsize'] = (8.267, 11.692) #aA paper
      fig = plt.figure()
      #plot all the 6 figures and save the 3x2 image as png
  
      ax1 = fig.add_subplot(321) # first row first image
      #compute all time 
      alltime = df['Close'].count()
      x,y,x_min, y_min, x_max, y_max = min_max(df,alltime)
      ax1.plot(x, y,'r')
      ax1.plot(x_min,y_min,'o')
      ax1.plot(x_max,y_max,'o')
      ax1.set_xlabel('year')
      ax1.set_ylabel('Index Close')
      ax1.set_title(plot_title[-1])
      ax1.fill_between(x,y,facecolor='red')
      ax1.annotate(y_min, xy=(x_min,y_min), xytext=(x_min,y_min +250))
      ax1.annotate(y_max, xy=(x_max,y_max), xytext=(x_max,y_max +250))
  
      ax2 = fig.add_subplot(322) # first row second image
      # compute ytd 
      ytd = df.ix[baseline_year:]['Close'].count()
      x,y,x_min, y_min, x_max, y_max = min_max(df,ytd)
      ax2.plot(x, y,'r')
      ....
      # repeat 4 more times for other figs
  
      fig.suptitle(key, fontsize=10)
      plt.tight_layout()
      plt.savefig(image)
  </code></pre>
  
  <p>How do I get the subplots into A4/6 equal sized plots with a little bit of space on top for the title?  as in 8.267/2 x 11.69/3 size?  The tight_layout helps but I'd like more control over the sizes and placement.</p>