title: Matplotlib - 2 problems. Common colorbar / labels not showing up
body: <p>I finally forced the 3 plots I want into one plot with 3 subplots...now I need to add a common colorbar, preferably horizontally oriented. Also, now that I have them as subplots, I have lost the labels that were there in a previous iteration. </p>
  
  <p>It seems that the examples suggest I <a href="http://matplotlib.org/examples/pylab_examples/multi_image.html" rel="nofollow noreferrer">add an axes</a>, but I don't quite get what the numbers in the arguments are. </p>
  
  <pre><code>def plot_that_2(x_vals, y_vals, z_1_vals, z_2_vals, z_3_vals, figname, units, efficiency_or_not):
      global letter_pic_width    
      plt.close()    #I moved this up from the end of the file because it solved my QTagg problem
      UI = [uniformity_calc(z_1_vals), uniformity_calc(z_2_vals), uniformity_calc(z_3_vals)]
      ranges = [ str(int(np.max(z_1_vals) - np.min(z_1_vals))), str(int(np.max(z_2_vals) - np.min(z_2_vals))), str(int(np.max(z_3_vals) - np.min(z_3_vals)))]
      z_vals = [z_1_vals, z_2_vals, z_3_vals]
  
      fig = plt.figure(figsize = (letter_pic_width, letter_pic_width/3 ))
      ax0 = fig.add_subplot(1,3,1, aspect = 1)
      ax1 = fig.add_subplot(1,3,2, aspect = 1)
      ax2 = fig.add_subplot(1,3,3, aspect = 1)
  
      axenames = [ax0, ax1, ax2]
  
      for z_val, unif, rangenum, ax in zip(z_vals, UI, ranges, axenames):
          ax.scatter(x_vals, y_vals, c = z_val, s = 100, cmap = 'rainbow')
          if efficiency_or_not:
              ax.vmin = 0
              ax.vmax = 1
              ax.xlabel = 'Uniformity: ' + unif
          else:
              ax.xlabel = 'Uniformity: ' + unif + '   ' + rangenum + ' ppm'
  
      plt.savefig('./'+ figname + '.jpg', dpi = 100) 
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/jcvkK.jpg" alt="This is the plot when efficiency = True. I think it&#39;s not setting the vmin / vmax, either."></p>