 <span class="n">len_arr</span> <span class="o">=</span> <span class="n">size_arr</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span>
    <span class="n">grid_points</span> <span class="o">=</span> <span class="n">size_arr</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="o">*</span> <span class="n">size_arr</span><span class="p">[</span><span class="mi">2</span><span class="p">]</span>
    <span class="n">rmse</span> <span class="o">=</