title: matplotlib savefig image size with bbox_inches='tight'
body: <p>I have to make a vector plot and I want to just see the vectors without the axes, titles etc so here is how I try to do it:</p>
  
  <pre><code>pyplot.figure(None, figsize=(10, 16), dpi=100)
  pyplot.quiver(data['x'], data['y'], data['u'], data['v'], 
                pivot='tail', 
                units='dots', 
                scale=0.2,
                color='black')
  
  pyplot.autoscale(tight=True)
  pyplot.axis('off')
  ax = pyplot.gca()
  ax.xaxis.set_major_locator(pylab.NullLocator())
  ax.yaxis.set_major_locator(pylab.NullLocator())
  pyplot.savefig("test.png", 
                 bbox_inches='tight', 
                 transparent=True,
                 pad_inches=0)
  </code></pre>
  
  <p>and despite my efforts to have an image 1000 by 1600 I get one 775 by 1280. How do I make it the desired size? 
  Thank you.</p>
  
  <p><strong>UPDATE</strong> The presented solution works, except in my case I also had to manually set the axes limits. Otherwise, matplotlib could not figure out the "tight" bounding box.</p>