title: How to set xlim in python matplotlib pyplot?
body: <p>I have this code:</p>
  
  <pre><code>import matplotlib.pyplot as pl
  pl.plot(np.log(alphas_lasso),coefs_lasso.T) #this generate a plot which xlim=[-8,-2]
  for alpha in alpha_min:
      pl.axvline(np.log(alpha),0,1) #add vertical line for every value of alpha
  pl.xlim([-10,0]) # the xlim value I would like to set
  pl.xlabel('Log(alpha)')
  pl.ylabel('coefficients')
  pl.title('Lasso Path')
  pl.axis('tight')
  pl.show()
  print "log(alpha_min)=",log(alpha_min)
  </code></pre>
  
  <p>It works but the x axis goes from -8 to -2 while I would like from -10 to 0 Where is the error? </p>