title: Prevent Matplotlib to stretch plot to only bbox of drawing area
body: <p>Please see below image:</p>
  <p><a href="https://i.stack.imgur.com/LvkUY.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/LvkUY.jpg" alt="enter image description here" /></a>
  I set the figure size of <code>plt</code> equal to something like <code>(4,6)</code> and set <code>axis</code> to <code>off</code> and <code>margin</code> to <code>zero</code>.
  Then continue to draw polyline using coordinate array by <code>ax.plot(line[:,1],line[:,0])</code></p>
  <p>after this I don’t use the <code>plt.show()</code>
  But convert the plot to numpy array which has correct (4,6) size but surprisingly fill the plot by stretched to only bbox of the draw line</p>
  <p>How can i see all the unused space of figure?</p>
  <p>Is there any flag that i have to change in somewhere in matplotlib?</p>
  <p>Any help appreciated</p>