span> <span class="n">ax</span><span class="o">=</span><span class="n">ax</span><span
            class="p">)</span>
    <span class="n">plt</span><span class="o">.</span><span class="n">xlabel</span><span class="p">(</span><span
            class="s2">&quot;t&quot;</span><span class="p">,</span> <span class="n">fontname</span><span
            class="o">=</span><span class="s1">&#39;Ubuntu&#39;</span><span class="p">,</span> <span
            class="n">fontsize</span><span class="o">=</span><span class="mi