title: Matplotlib.patches.Wedge animation not working
body: <p>I have just started animating my matplotlib patches. In my current work, I want to display a visualization where there exist a wedge that change it size through time. However, I am getting a static wedge, for a reason beyond my vision.</p>
  
  <pre><code>#!/usr/bin/env python
  import numpy as np
  from matplotlib import pyplot as plt
  from matplotlib import animation
  import matplotlib.patches
  
  # First set up the figure, the axis, and the plot element we want to animate
  fig = plt.figure()
  ax = plt.axes(xlim=(-2, 2), ylim=(-2, 2))
  plt.grid(True)
  # patch_one = matplotlib.patches.Circle((0, 0), 1)
  patch_one = matplotlib.patches.Wedge((0,0), 1, -10, 10)
  
  # initialization function: plot the background of each frame
  def init():
      patch_one.radius = 1
      ax.add_patch(patch_one)
      return patch_one,
  
  # animation function.  This is called sequentially
  def animate(i):
      patch_one.radius +=i*0.0001
      return patch_one,
  
  # call the animator.  blit=True means only re-draw the parts that have changed.
  anim = animation.FuncAnimation(fig, animate, init_func=init,
                                 frames=200, interval=20, blit=True)
  
  plt.show()
  </code></pre>
  
  <p>I tried the code by replacing patch_one by a circular patch and it did work (left that part commented out in the code). </p>