sure variable (<span class="math inline">\(X\)</span>).</p>
<div class="sourceCode" id="cb6"><pre class="sourceCode r"><code class="sourceCode r"><a class="sourceLine" id="cb6-1" data-line-number="1">dat2 &lt;-<span class="st"> </span>dat </a>
<a class="sourceLine" id="cb6-2" data-line-number="2">dat2<span class="op">$</span>Y &lt;-<span class="st"> </span><span class="kw">ifelse</span>(dat<span class="op">$</span>Y <span class="op">==</span><span class="st"> </span><span class="dv">1</span>, <span class="k