lass="n">coeffs</span> <span class="o">=</span> <span class="p">[</span><span class="o">-</span><span class="mf">1.0</span> <span class="o">/</span> <span class="mf">2.0</span><span class="p">,</span> <span class="mf">1.0</span> <span class="o">/</span> <span class="mf">2.0</span><span class="p">]</span>
        <span class="n">deltas</span> <span class="o">=</span> <span class="p">[</span><span class="o">-</span><span class="mf">1.0</span><span class="p">,</span> <span class="mf">1.0</span><span class="p">