title: How to format a polar contour plot in matplotlib
body: <p>I have some sample code to make a polar contour plot:</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  
  azimuths = np.radians(np.linspace(0, 180, 90))
  zeniths = np.arange(50, 5050, 50)
  
  r, theta = np.meshgrid(zeniths, azimuths)
  values = 90.0+5.0*np.random.random((len(azimuths), len(zeniths)))
  
  fig, ax = plt.subplots(subplot_kw=dict(projection='polar'))
  ax.set_theta_zero_location("W")
  pp = plt.contourf(theta, r, values, label='tmp')
  cbar = plt.colorbar(pp, orientation='vertical')
  cbar.ax.set_ylabel('scale label')
  plt.show()
  </code></pre>
  
  <p>which gives me something like:</p>
  
  <p><img src="https://i.stack.imgur.com/0ILxe.png" alt="enter image description here"></p>
  
  <p>...but I would like something more like this:</p>
  
  <p><img src="https://i.stack.imgur.com/OzhVe.jpg" alt="enter image description here"></p>
  
  <p>...with space in the middle, and only showing 0 to 180 degrees. Does anyone know of a convenient way to do this?</p>