y <code>[N / 2][1]</code> to
         <code>[N][n + 1]</code>,</li>
         <li>the columns of <code>D_bottom</code> are the pairwise differences
         of the previous column.</li>
     </ul>
 </li>
 <li>The consputation of <code>D_top</code> and <code>D_bottom</code> are best
 understood with the above example (for <code>N = 8</code>).
 <li>The output vector <code>y</code> is now in the last column of
 <code>hadm</code>.</li>
 <li><em>Algorithm from <a href="http://www.archive.chipcenter.com/dsp/DSP000