title: Normed histogram y-axis larger than 1
body: <p>Sometimes when I create a histogram, using say seaborn's displot function, with norm_hist = True, the y-axis is less than 1 as expected for a PDF. Other times it takes on values greater than one. </p>
  
  <p>For example if I run </p>
  
  <pre><code>        sns.set(); 
          x = np.random.randn(10000)
          ax = sns.distplot(x)
  </code></pre>
  
  <p>Then the y-axis on the histogram goes from 0.0 to 0.4 as expected, but if the data is not normal the y-axis can be as large as 30 even if norm_hist = True.</p>
  
  <p>What am I missing about the normalization arguments for histogram functions, e.g. norm_hist for sns.distplot? Even if I normalize the data myself by creating a new variable thus:</p>
  
  <pre><code>        new_var = data/sum(data)
  </code></pre>
  
  <p>so that the data sums to 1, the y-axis will still show values far larger than 1 (like 30 for example) whether the norm_hist argument is True or not.  </p>
  
  <p>What interpretation can I give when the y-axis has such a large range? </p>
  
  <p>I think what is happening is my data is concentrated closely around zero so in order for the data to have an area equal to 1 (under the kde for example) the height of the histogram has to be larger than 1...but since probabilities can't be above 1 what does the result mean?</p>
  
  <p>Also, how can I get these functions to show probability on the y-axis?</p>