title: Plotting dashed 2D vectors with matplotlib?
body: <p>I'm using <code>quiver</code> to draw vectors in matplotlib:</p>
  
  <pre><code>from itertools import chain
  import matplotlib.pyplot as pyplot
  pyplot.figure()
  pyplot.axis('equal')
  axis = pyplot.gca()
  axis.quiver(*zip(*map(lambda l: chain(*l), [
      ((0, 0), (3, 1)),
      ((0, 0), (1, 0)),
  ])), angles='xy', scale_units='xy', scale=1)
  
  axis.set_xlim([-4, 4])
  axis.set_ylim([-4, 4])
  pyplot.draw()
  pyplot.show()
  </code></pre>
  
  <p>which gives me nice arrows, but how can I change their line style to dotted, dashed, etc.?</p>