re class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="va">dfm</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/data.frame.html" class="external-link">data.frame</a></span><span class="op">(</span>x1 <span class="op">=</span> <span class="va">letters</span><span class="op">[</span><span class="fl">1</span><span class="op">:</span><span class="fl">7</span><span class="op">]</span>, <span class="va">x2</span><span class="op">)</span></span>
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