title: Animation of histograms in subplot
body: <p>I have the following animated subplots that simulate histograms of four different distributions:</p>
  
  <pre><code>import numpy
  from matplotlib.pylab import *
  import matplotlib.animation as animation
  
  n = 100
  
  # generate 4 random variables from the random, gamma, exponential, and uniform distributions
  x1 = np.random.normal(-2.5, 1, 10000)
  x2 = np.random.gamma(2, 1.5, 10000)
  x3 = np.random.exponential(2, 10000)+7
  x4 = np.random.uniform(14,20, 10000)
  
  fig, ((ax1, ax2), (ax3, ax4)) = plt.subplots(2, 2)
  
  def updateData(curr):
  
      if curr == n: 
          a.event_source.stop()
  
      ax1.hist(x1[:curr], normed=True, bins=20, alpha=0.5)
      ax2.hist(x2[:curr], normed=True, bins=20, alpha=0.5)
      ax3.hist(x3[:curr], normed=True, bins=20, alpha=0.5)
      ax4.hist(x4[:curr], normed=True, bins=20, alpha=0.5)
  
  simulation = animation.FuncAnimation(fig, updateData, interval=20, repeat=False)
  
  plt.show()
  </code></pre>
  
  <p>It works, but for some reason the normed=True is being ignored for the y-axis scaling. If I take these plots out of the animation, they scale properly. How do I get proper scaling in the animation?</p>
  
  <p><strong><em>EDIT</em></strong></p>
  
  <p>Instead of having a scale like this (outside of animation):<a href="https://i.stack.imgur.com/uDlAE.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/uDlAE.png" alt="no animation"></a></p>
  
  <p>I get (inside of animation): <a href="https://i.stack.imgur.com/3TupP.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3TupP.png" alt="animation"></a></p>