ter string of the variable name in the dataset
that is the ID variable.</p></td>
    </tr>
    <tr>
      <th>assessmentvar</th>
      <td><p>A character string of the variable name in the dataset that
indicates the particular assessment point for each timepoint.</p></td>
    </tr>
    <tr>
      <th>newdata</th>
      <td><p>A data frame of new values to use for generating predicted
trajectories by class or <code>FALSE</code> if no predictions to be made
(the default).</p></td>
    </tr>
    <tr>
      <th