n class="p">,</span><span class="n">m</span> <span class="o">=</span> <span class="mi">1</span><span class="p">:</span><span class="n">mdm</span><span class="p">)</span>

    <span class="n">dfdt</span><span class="p">(</span><span class="n">m</span><span class="p">,</span><span class="n">i</span><span class="p">,</span><span class="n">j</span><span class="p">)</span> <span class="o">=</span> <span class="o">-</span> <span class="mf">0.25_rk</span>                                  <span class="p">&amp;</spa