r beta. Defaults to NULL, in which case the starting values outlined in the paper are used.</p></td>
    </tr>
    <tr>
      <th>formula</th>
      <td><p>A formula object of the form \(y ~ x | group\). Required with
the <code>data</code> argument.</p></td>
    </tr>
    <tr>
      <th>data</th>
      <td><p>A dataframe containing the response, response standard errors, covariates,
and grouping variable. Required with the <code>formula</code> argument.</p></td>
    </tr>
    </table>

    <h2 class="hasAnc