<dt>date_var</dt>
<dd><p>the name of the column in <code>x</code> for dates.</p></dd>


<dt>span</dt>
<dd><p>the level of smoothing.</p></dd>


<dt>group</dt>
<dd><p>the name of the column in <code>x</code> to smooth the data by group.</p></dd>


<dt>from, to, by</dt>
<dd><p>the the range and the internal of the smoothed scores;
passed to <a href="https://rdrr.io/r/base/seq.Date.html" class="external-link">seq.Date</a>.</p></dd>


<dt>engine</dt>
<dd><p>specifies the function to be used for smoothing.</p></