it calculation to only a subset of variables, use the <code>variables</code> argument:</p>
<div class="sourceCode"><pre class="sourceCode r"><code class="sourceCode r"><span class="kw">summary</span>(<span class="kw"><a href="../reference/margins.html">margins</a></span>(x, <span class="dt">variables =</span> <span class="st">"hp"</span>))</code></pre></div>
<pre><code>##  factor     AME     SE       z      p   lower   upper
##      hp -0.0253 0.0105 -2.4046 0.0162 -0.0459 -0.0047</code></pre>
<p>In an ordi