<span class='op'>(</span><span class='st'>"thickness"</span><span class='op'>)</span>,
  subj_dir <span class='op'>=</span> <span class='cn'>NULL</span>,
  opts <span class='op'>=</span> <span class='st'>""</span>,
  verbose <span class='op'>=</span> <span class='cn'>TRUE</span>
<span class='op'>)</span></pre>

    <h2 class="hasAnchor" id="arguments"><a class="anchor" href="#arguments"></a>Arguments</h2>
    <table class="ref-arguments">
    <colgroup><col class="name" /><col class="desc" /></colgroup>
   