n class="mf">1e7</span>
        <span class="n">step_</span> <span class="o">=</span> <span class="n">x_max</span> <span class="o">-</span> <span class="n">x_min</span>
        <span class="n">axis</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">array</span><span class="p">([</span><span class="n">x_min</span><span class="o">+</span><span class="n">j</span><span class="o">*</span><span class="n">step_</span><span class="o">/</span><span class="bp">self</span>