title: using ols from statsmodels.formula.api - how to remove constant term?
body: <p>I'm following this first example in <code>statsmodels</code> tutorial:</p>
  
  <p><a href="http://statsmodels.sourceforge.net/devel/" rel="noreferrer">http://statsmodels.sourceforge.net/devel/</a></p>
  
  <p>How do I specify not to use constant term for linear fit in ols?</p>
  
  <pre><code># Fit regression model (using the natural log of one of the regressors)
  results = smf.ols('Lottery ~ Literacy + np.log(Pop1831)', data=dat).fit()
  </code></pre>