title: PyPlot reverse y-axis and logarithmic
body: <p>Is there a way to both reverse the y-axis with <code>PyPlot</code> and make it logarithmic? I know that one of the two options can be done with</p>
  
  <pre><code>plt.gca().invert_yaxis()
  </code></pre>
  
  <p>and</p>
  
  <pre><code>plt.yscale('log')
  </code></pre>
  
  <p>However, the combination does not work. Any ideas? Thanks a lot!</p>