title: Why doesn't stats.sem() recognize the nan_policy keyword?
body: <p>Code: </p>
  
  <pre><code>e = [1, 2, 3, 4, 5]
  s = stats.sem(e, nan_policy = 'omit')
  </code></pre>
  
  <p>Error: </p>
  
  <pre><code>sem() got an unexpected keyword argument 'nan_policy'
  </code></pre>
  
  <p>I don't understand why I'm getting this error; 'nan_policy' is a perfectly <a href="http://docs.scipy.org/doc/scipy/reference/generated/scipy.stats.sem.html" rel="nofollow">acceptable</a> parameter for <code>stats.sem()</code>. </p>