an>, then the discrete Lanczos derivative is not smoothing:
      It reduces to the standard <span class="emphasis"><em>2n+1</em></span>-point finite-difference
      formula. For <span class="emphasis"><em>p&gt;2n</em></span>, an assertion is hit as the filter
      is undefined.
    </p>
<p>
      In our tests with AWGN, we have found the error decreases monotonically with
      <span class="emphasis"><em>n</em></span>, as is expected from the theory discussed above. So
      the choice of <span class="em