e>what</code> options narrows the range of
what is being shown:</p></li>
<li><p>To only visualize a bare tree diagram (without performance
statistics), we specify <code>what = "tree"</code> (formerly
<code>stats = FALSE</code>).</p></li>
<li><p>To visualize the tree diagram with icon arrays on exit nodes, we
specify <code>what = "icontree"</code> (with additional options for
<code>show.iconguide</code> and <code>n.per.icon</code>).</p></li>
<li><p>To visualize the performance comparison (for different FFTs 