title: matplotlib streamplot compresses the lines
body: <p>I'm struggling to plot streamlines using matplotlib1.2 but I noticed it compress the line spaces in y direction. My data in y direction is from 0.5-1.5 but the streamlines are plotted between 0.5-1.04. They looks correct and as I expect but I can not use them in my paper due to this compression. Is there way I can fix it? I bring the script I use below.</p>
  
  <pre><code>r=loadtxt('used_rad.dat')
  r1=r[:-1]
  Nr=256
  Ns=512
  dthet=2*pi/Ns
  theta=arange(Ns)*dthet
  vr=fromfile('gasvrad1000.dat')
  vt=fromfile('gasvtheta1000.dat')
  vr.resize(Nr,Ns)
  vt.resize(Nr,Ns)
  streamplot(theta,r1,vt,vr,density=3)
  </code></pre>
  
  <p>I can't post the image since I don't have enough reputation but if anyone needs to see the plot I can send it by email.</p>