</span><span class="n">np</span><span class="o">.</span><span class="n">vstack</span><span class="p">([</span><span class="n">X1</span><span class="o">.</span><span class="n">ravel</span><span class="p">(),</span> <span class="n">Y1</span><span class="o">.</span><span class="n">ravel</span><span class="p">()]))</span><span class="o">.</span><span class="n">reshape</span><span class="p">(</span><span class="n">X1</span><span class="o">.</span><span class="n">shape</span><span class="p">)</span>

    <span cl