pan><span class="p">]</span>
    <span class="n">bt</span> <span class="o">=</span> <span class="n">labt</span><span class="p">[</span><span class="o">...</span><span class="p">,</span><span class="mi">2</span><span class="p">:</span><span class="mi">3</span><span class="p">]</span>
    <span class="n">Ct</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">sqrt</span><span class="p">(</span><span class="n">at</span><span class="o">**</span><span class="mi">2</spa