ow_freq<a class="anchor" aria-label="anchor" href="#arg-low-freq"></a></dt>
<dd><p>Number indicating the lowest period of oscillation as fractions of \(\pi\).
If <code>low_freq &gt; 1</code>, indicating that the direct frequency of the data is
provided, this is transformed internally into <code>2 / high_freq</code>. The default
is <code>NULL</code>, meaning that the <code>ifelse(freq &gt; 1, trunc(freq * 1.5), 2)</code>
will be used.</p></dd>

<dt id="arg-high-freq">high_freq<a class="anchor" aria-label="an