><span class="mi">1</span><span class="p">])</span>

        <span class="c1"># If the results are of the same length, we can simply concatenate them</span>
        <span class="c1"># into one numpy array. Otherwise we will return a regular python list.</span>
        <span class="n">der_lists</span> <span class="o">=</span> <span class="p">[</span><span class="n">x</span><span class="p">[</span><span class="mi">0</span><span class="p">][</span><span class="mi">0</span><span class="p">]</span> <span class="