title: matplotlib slider not working when called from a function
body: <p>I have the following code, which shows a graph with a slinding bar</p>
  
  <pre><code>    from matplotlib.widgets import Slider
      import matplotlib.pyplot as plt
      from numpy import arange, sin, pi
  
      t = arange(0.0, 10.0, 0.01)
  
      fig =plt.figure(figsize = [30,20])
      ax = plt.subplot(111)
      plt.plot(t, sin(t*10))
      plt.ylim((-2,2))
      plt.xlim((0,1))
      plt.tight_layout()
  
      axzoom= plt.axes([0.15, 0.05, 0.65, 0.03])
      szoom = Slider(axzoom, 'Window', 1, 2)
  
      def update(val):
          ax.set_xlim([val,val+1])
          fig.canvas.draw_idle()
      szoom.on_changed(update)
      plt.show()
  </code></pre>
  
  <p>I want to call it from a function, that is: </p>
  
  <pre><code>def myplot(): 
      (... same code as above)
  </code></pre>
  
  <p>The problem is, when I do that the slinding bar does not work anymore. Any  idea of what I could be doing wrong? </p>
  
  <p>I am trying to execute it from iPython within Spyder. 
  Thank you for any help. </p>