title: Plotting patches of random shapes with matplotlib
body: <p>This is my target to plot:<br />
  Several ellipses which are not regular shape.</p>
  <p><a href="https://i.stack.imgur.com/hv9Qd.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/hv9Qd.png" alt="" /></a><br />
  <sub>(source: <a href="http://7xrn7f.com1.z0.glb.clouddn.com/16-3-12/7568305.jpg" rel="nofollow noreferrer">clouddn.com</a>)</sub></p>
  <p>I was thinking about generating some random number as vertices location.</p>
  <p>But it can only build a polygon. So, how to plot several arcs and make them close up?</p>