�
which is why <code><a href="https://rdrr.io/r/graphics/plot.default.html" class="external-link">plot()</a></code> will show the best training tree (with
a warning).</p></li>
</ol>
</div>
<div class="section level3">
<h3 id="plotting-performance-for-new-data">Plotting performance for new data<a class="anchor" aria-label="anchor" href="#plotting-performance-for-new-data"></a>
</h3>
<p>Shifting our emphasis from fitting to prediction, we primarily need
to specify some test data that was not used to train the