title: `rms::ols()`: how to fit a model without intercept
body: <p>I'd like to use the <code>ols()</code> (ordinary least squares) function from the <code>rms</code> package to do a multivariate linear regression, but I would not like it to calculate the intercept. Using <code>lm()</code> the syntax would be like:</p>
  
  <pre><code>model &lt;- lm(formula = z ~ 0 + x + y, data = myData)
  </code></pre>
  
  <p>where the <code>0</code> stops it from calculating an intercept, and only two coefficients are returned, on for <code>x</code> and the other for <code>y</code>. How do I do this when using <code>ols()</code>? 
  Trying</p>
  
  <pre><code>model &lt;- ols(formula = z ~ 0 + x + y, data = myData)
  </code></pre>
  
  <p>did not work, it still returns an intercept and a coefficient each for <code>x</code> and <code>y</code>.</p>
  
  <p><a href="https://www.dropbox.com/s/jp0oxl4p1ahzaag/ccd.csv" rel="nofollow">Here is a link to a csv file</a></p>
  
  <p>It has five columns. For this example, can only use the first three columns:</p>
  
  <pre><code>model &lt;- ols(formula = CorrEn ~ intEn_anti_ncp + intEn_par_ncp, data = ccd)
  </code></pre>
  
  <p>Thanks!</p>