m</a></h4>
  <dl>
  <dt>Expand</dt>
  <dd>
  <p>Scaling factor to shrink/expand the spectrum along to frequency
  axis.</p>
  <p><img src="img/expand.svg" /></p>
  </dd>
  <dt>Shift</dt>
  <dd>
  <p>Shift spectrum along to frequency axis.</p>
  <p><img src="img/shift.svg" /></p>
  </dd>
  <dt>Comb</dt>
  <dd>
  <p>When this value is higher than 1, it changes the shape of profile
  like a comb. The value specifies interval between peaks.</p>
  <p><img src="img/comb.png" /></p>
  </dd>
  <dt>Shape</dt>
  <dd>