sonal_onset()</a></code> function provides a
<code>tsd_onset</code> object with a comprehensive seasonal onset
analysis.</p>
<p><em>NOTE: </em>As default the output is in cases, but if
<code>incidence</code> and <code>population</code> is in the
<code>tsd</code> object the average observations will be in incidence
and the model will use <code>population</code> as offset in each time
point.</p>
<div class="sourceCode" id="cb3"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="v