o">.</span><span class="n">matshow</span><span class="p">(</span><span class="n">M</span><span class="p">,</span> <span class="n">origin</span><span class="o">=</span><span class="s1">&#39;lower&#39;</span><span class="p">)</span>
    <span class="n">fig</span><span class="o">.</span><span class="n">colorbar</span><span class="p">(</span><span class="n">cax</span><span class="p">)</span>
    <span class="n">ax</span><span class="o">.</span><span class="n">set_xticks</span><span class="p">([])</span>
    <sp