title: How to normalize an histogram
body: <p>I have this histogram which counts the array "d" in equally log-spaced bins.</p>
  
  <pre><code> max_val=np.log10(max(d))
   min_val=np.log10(min(d))
   logspace = np.logspace(min_val, max_val, 50) 
  
  
   hist(d,bins=logspace,label='z='+str(redshift),histtype='step')
   show()
  </code></pre>
  
  <p>The problem is that I want it to be normalized so as the area is one. Using the option Normed=True I didn't get the result, it might be due to fact that I'm using logarithmic bins. Therefore I tried normalizing the histogram in this way:</p>
  
  <pre><code> H=hist(d,bins=logspace,label='z='+str(redshift),histtype='step')
   H_norm=H[0]/my_norm_constant
  </code></pre>
  
  <p>But then I don't know how to plot H_norm versus the bins</p>