title: Python animation polar plot
body: <p>I tried to create an animation with this plot, where with the increase of 'beta' the curves go stretching, but I could not. Please, can anyone help me?</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  from matplotlib.animation import FuncAnimation 
  
  # Data:
  mu = 1
  e = 1
  a = 1
  c = 1
  beta = np.linspace(0.0 ,0.5,25)
  C = (mu*((e*a)**2)) / (16*(np.pi**2)*c) 
  
  theta = np.linspace(-2 * np.pi, 2 * np.pi, 200)
  
  fig = plt.figure(figsize=(6,6))
  ax = plt.subplot(111, polar=True)
  
  for i in range(len(beta)):
      b = beta[i]
      r = ((np.sin(theta))**2) / ((1 - b*np.cos(theta))**5)
      dP = C*r
      ax.plot(theta, dP)
      ax.set_yticklabels([])
      if i==10000:
          break
  
  plt.show() 
  </code></pre>