title: How to convert data values into color information for matplotlib?
body: <p>I am using the class matplotlib.patches.Polygon to draw polygons on a map. In fact, the information about the coordinates of the corners of the polygons and a floating point data value for each "polygon" are given.
  Now I'd like to convert these data values (ranging from 0 to 3e15) into color information to visualize it nicely. What is the best practice for doing that in Python?</p>
  
  <p>A snippet of my code:</p>
  
  <pre><code>poly = Polygon( xy, facecolor=data, edgecolor='none')
  plt.gca().add_patch(poly)
  </code></pre>