title: How to tune GaussianNB?
body: <p>Trying to fit data with <a href="http://scikit-learn.org/stable/modules/generated/sklearn.naive_bayes.GaussianNB.html#sklearn.naive_bayes.GaussianNB" rel="noreferrer"><code>GaussianNB()</code></a> gives me low accuracy score.</p>
  
  <p>I'd like to try Grid Search, but it seems that parameters <code>sigma</code> and <code>theta</code> cannot be set. Is there anyway to tune <code>GausssianNB</code>?</p>