title: Matplotlib's 3D Graph does not show anything
body: <p>I want to make a 3D Graph with Matplotlib. The graph window appears, but no data is shown. What am I doing wrong?</p>
  
  <pre><code>import numpy as np
  import matplotlib.pyplot as plt
  from mpl_toolkits.mplot3d import Axes3D
  
  fig = plt.figure()
  ax = fig.add_subplot(111, projection='3d')
  
  x = [0, 10, 20, 40, 100]
  y = [1, 4, 8, 60, 200]
  z = [4, 5, 6, 7, 8]
  
  
  ax.plot_surface(x, y, z)
  
  plt.show()
  </code></pre>