s="o">.</span><span class="n">norm</span><span class="p">(</span><span class="n">vec</span> <span class="o">-</span> <span class="n">vec1</span><span class="p">)</span> <span class="o">&lt;</span> <span class="mf">1e-6</span><span class="p">:</span>
                <span class="n">central_mats</span> <span class="o">=</span> <span class="kc">None</span>
            <span class="k">else</span><span class="p">:</span>
                <span class="n">c_vec</span> <span class="o">=</span> <span class="n">np</sp