title: Plot logarithmic axes with matplotlib in python
body: <p>I want to plot a graph with one logarithmic axis using matplotlib. </p>
  
  <p>I've been reading the docs, but can't figure out the syntax. I know that it's probably something simple like <code>'scale=linear'</code> in the plot arguments, but I can't seem to get it right</p>
  
  <p>Sample program: </p>
  
  <pre><code>import pylab
  import matplotlib.pyplot as plt
  a = [pow(10, i) for i in range(10)]
  fig = plt.figure()
  ax = fig.add_subplot(2, 1, 1)
  
  line, = ax.plot(a, color='blue', lw=2)
  pylab.show()
  </code></pre>