title: Latex and text in matplotlib title
body: <p>I'm trying to show an image with a title that combines normal text with a couple of Latex commands:</p>
  
  <pre><code>plt.imshow(w1subtracted2, origin='lower',
            extent=[l_max, -l_max, -b_max, b_max],
            cmap = color_map)
  plt.title('W1 disk and central $\pm2\textdegree$ subtracted', fontsize = 'small')
  plt.xlabel(xlabel, fontsize = 'small')
  plt.ylabel(ylabel, fontsize = 'small')
  plt.savefig('w1subtracted2.png')
  </code></pre>
  
  <p>but I can't get the title showing the <code>\pm</code> and <code>\textdegree</code> to show in Latex style. How can I achieve that?</p>