ow</code> variable represents the
average of cases over a five-week window, which is used to define the
disease-specific threshold.</p>
<div class="sourceCode" id="cb3"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="va">tsd_onset</span> <span class="op">&lt;-</span> <span class="fu"><a href="../reference/seasonal_onset.html">seasonal_onset</a></span><span class="op">(</span></span>
<span>  tsd <span class="op">=</span> <span class="va">tsd_data</span>,</span>
<span>  k <spa