title: How do I tell Matplotlib to create a second (new) plot, then later plot on the old one?
body: <p>I want to plot data, then create a new figure and plot data2, and finally come back to the original plot and plot data3, kinda like this:</p>
  
  <pre><code>import numpy as np
  import matplotlib as plt
  
  x = arange(5)
  y = np.exp(5)
  plt.figure()
  plt.plot(x, y)
  
  z = np.sin(x)
  plt.figure()
  plt.plot(x, z)
  
  w = np.cos(x)
  plt.figure("""first figure""") # Here's the part I need
  plt.plot(x, w)
  </code></pre>
  
  <p>FYI <a href="https://stackoverflow.com/questions/741877/how-do-i-tell-matplotlib-that-i-am-done-with-a-plot">How do I tell matplotlib that I am done with a plot?</a> does something similar, but not quite! It doesn't let me get access to that original plot.</p>