title: how to use matplotlib's set_cmap()?
body: <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  
  x=np.linspace(-np.pi,np.pi,101)
  y=np.sin(x)+np.sin(3*x)/3
  y1=np.sin(x)+np.sin(2*x)/3
  y2=np.sin(x)+np.sin(3*x)/2
  
  plt.set_cmap('hot')
  
  plt.plot(x,y)
  plt.plot(x,y1)
  plt.plot(x,y2)
  plt.show()
  </code></pre>
  
  <p>I wanted to try a different colormap in my plot, but the command <code>plt.set_cmap('hot')</code> does not work, i.e. the colours are the same as in the standard palette ( <a href="http://i.stack.imgur.com/FjXoO.png" rel="noreferrer">http://i.stack.imgur.com/FjXoO.png</a>)</p>
  
  <p>I am using WXAgg backend under Debian Linux and matplotlib from Enthought's Canopy. I tried the Qt4Agg backend and the result was the same. How to properly change the colours?</p>