title: how to handle an asymptote/discontinuity with Matplotlib
body: <p>When plotting a graph with a discontinuity/asymptote/singularity/whatever, is there any automatic way to prevent Matplotlib from 'joining the dots' across the 'break'? (please see code/image below).<br>
  I read that Sage has a [detect_poles] facility that looked good, but I really want it to work with Matplotlib.</p>
  
  <pre><code>import matplotlib.pyplot as plt 
  import numpy as np
  from sympy import sympify, lambdify
  from sympy.abc import x
  
  fig = plt.figure(1) 
  ax = fig.add_subplot(111) 
  
  # set up axis 
  ax.spines['left'].set_position('zero') 
  ax.spines['right'].set_color('none') 
  ax.spines['bottom'].set_position('zero') 
  ax.spines['top'].set_color('none') 
  ax.xaxis.set_ticks_position('bottom') 
  ax.yaxis.set_ticks_position('left') 
  
  # setup x and y ranges and precision
  xx = np.arange(-0.5,5.5,0.01) 
  
  # draw my curve 
  myfunction=sympify(1/(x-2))
  mylambdifiedfunction=lambdify(x,myfunction,'numpy')
  ax.plot(xx, mylambdifiedfunction(xx),zorder=100,linewidth=3,color='red') 
  
  #set bounds 
  ax.set_xbound(-1,6)
  ax.set_ybound(-4,4) 
  
  plt.show()
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/df2aZ.png" alt="Discontinuity"></p>