pan><span class="o">.</span><span class="n">x</span><span class="o">.</span><span class="n">shape</span><span class="p">[</span><span class="mi">0</span><span class="p">]):</span>
        <span class="k">if</span> <span class="n">n</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class="o">!=</span> <span class="mf">0.0</span><span class="p">:</span>
            <span class="n">e_x</span><span class="p">[</span><span class="n">j</span><span class="p">]</span> <span class=