  <td><p>Points representing origins of OD flows
(typically population-weighted centroids)</p></td>
    </tr>
    <tr>
      <th>cols</th>
      <td><p>A character vector containing the names of columns on which to
apply FUN. By default, all numeric columns are aggregated.</p></td>
    </tr>
    <tr>
      <th>aggcols</th>
      <td><p>A character vector containing the names of columns in
aggzones to retain in the aggregated data.frame. By default,
only the first column is retained. These columns are rename