title: How to speed up pandas.DataFrame plotting?
body: <p>I am building a GUI in PySide where I have to keep redrawing <code>pandas.DataFrame</code> objects.  </p>
  
  <p>I found out in this simple snippet of code that plotting the pandas DataFrame object <code>df</code> takes much longer to plot than the <code>numpy.array</code> object, despite the fact that the plots are nearly identical.  This is too slow for my GUI.  Why is this so much slower?</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  import pandas as pd
  
  data = np.cumsum(np.random.randn(100, 10), axis=0)
  df = pd.DataFrame(data)
  
  df.plot()  # Compare the speed of this line... (slow)
  plt.plot(data)  # to this line. (fast)
  </code></pre>
  
  <p>I like the way that the <code>pandas.DataFrame</code> plots look, especially because in my real example my x-axis is <code>datetime</code> data from <code>pandas</code>.  I do not know how to format a <code>matplotlib.pyplot</code> x-axis to look good with <code>datetime</code> data.</p>
  
  <p><strong>How do I speed up <code>pandas.DataFrame</code> plotting?</strong></p>