/span></span></code></pre></div>
    </div>

    <div id="arguments">
    <h2>Arguments</h2>


<dl><dt id="arg--df">.df<a class="anchor" aria-label="anchor" href="#arg--df"></a></dt>
<dd><p>A data.frame or data.table</p></dd>


<dt id="arg--">...<a class="anchor" aria-label="anchor" href="#arg--"></a></dt>
<dd><p>Columns to create/modify</p></dd>


<dt id="arg--by">.by<a class="anchor" aria-label="anchor" href="#arg--by"></a></dt>
<dd><p>Columns to group by</p></dd>

</dl></div>

    <div id="ref-examples">