title: Matplotlib : display array values with imshow
body: <p>I'm trying to create a grid using a <code>matplotlib</code> function like <code>imshow</code>.<br>
  From this array:    </p>
  
  <pre><code>[[ 1  8 13 29 17 26 10  4],
  [16 25 31  5 21 30 19 15]]
  </code></pre>
  
  <p>I would like to plot the value as a color AND the text value itself (1,2, ...) on the same grid. This is what I have for the moment (I can only plot the color associated to each value):  </p>
  
  <pre><code>from matplotlib import pyplot
  import numpy as np
  
  grid = np.array([[1,8,13,29,17,26,10,4],[16,25,31,5,21,30,19,15]])
  print 'Here is the array'
  print grid
  
  fig1, (ax1, ax2)= pyplot.subplots(2, sharex = True, sharey = False)
  ax1.imshow(grid, interpolation ='none', aspect = 'auto')
  ax2.imshow(grid, interpolation ='bicubic', aspect = 'auto')
  pyplot.show()   
  </code></pre>