g yields a very large
dataframe, possibly overflowing memory.</p></td>
    </tr>
    </table>
    
    <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2>

    <p>The data frame <code>x</code> with the datetime variable padded. All
non-grouping variables in the data frame will have missing values at the rows
that are padded. The result will always be sorted on the datetime variable.
If <code>group</code> is not <code>NULL</code> result is sorted on grouping variable(s)
first, the