title: How to embed vispy graph in PyQt?
body: <p>I'm trying to embed a vispy plot (more specifically, a Vispy SceneCanvas) as a QWidget into PyQt4. I would presume the answer would be something like this:</p>
  
  <pre><code>from PyQt4.QtCore import *
  from PyQt4.QtGui import *
  import vispy.mpl_plot as plt
  
  app = QApplication(sys.argv)
  win = QMainWindow()
  plt.plot([1,2,3,4], [1,4,9,16])
  vispyCanvas=plt.show()[0]
  win.setCentralWidget(vispyCanvas)
  </code></pre>
  
  <p>However, when I try this the last line gives me the expected error that vispyCanvas is type <code>SceneCanvas</code> and not of type <code>QWidget</code>.  When I <code>print(vispyCanvas)</code>, it prints out <code>&lt;Vispy canvas (PyQt4 (qt) backend) at 0x142bcb00L&gt;</code>, which is why I suspect that it should be possible to treat it or one of its attributes as a QWidget object.</p>