/span><span class="p">]</span><span class="o">.</span><span class="n">index</span><span class="p">(</span><span class="s1">&#39;nino3.4&#39;</span><span class="p">)</span>
</pre></div>
</div>
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<p>We use a chain calling of several methods, including the validation step <code class="docutils literal notranslate"><span class="pre">.validate()</span></code> and the plotting step <code class="docutils literal notranslate"><span class="pre">.plot_qs()</span></code>.</p>
<div class="nbinput docutils containe