 column of results reveal that the average marginal effect of <code>wt</code> is large and negative except when <code>wt</code> is very large, in which case it has an effect not distinguishable from zero. We can easily plot these results using the <code><a href="../reference/cplot.html">cplot()</a></code> function to see the effect visually in terms of either predicted fuel economy or the marginal effect of <code>wt</code>:</p>
<div class="sourceCode"><pre class="sourceCode r"><code class="sourceCode r"><sp