title: Fixing the intercept in statsmodels ols
body: <p>In Python's <code>statsmodels.formula.api</code>, the ols functionality automatically includes and estimates an intercept:</p>
  
  <pre><code>results = sm.ols(formula="s ~ x + y + z", data=somedata).fit()
  results.params
  (* Intercept 0.632646, x -1.258761, y 0.465076, z 0.497991 *)
  </code></pre>
  
  <p>Because I'm using it in a linear probability model, is there any way to fix the intercept to 0.5?</p>