span><span class="n">i_sample</span><span class="p">]</span> <span class="o">=</span> <span class="n">i_der</span>
                <span class="k">else</span><span class="p">:</span>
                    <span class="n">derivatives</span><span class="o">.</span><span class="n">append</span><span class="p">(</span><span class="n">i_der</span><span class="p">)</span>

                <span class="k">if</span> <span class="n">verbose</span><span class="p">:</span>
                    <span class="n">current_per