">(</span><span class="va">obs</span>, <span class="va">grp1</span>, <span class="va">grp2</span>, <span class="va">noise</span><span class="op">)</span></span>
<span><span class="fu"><a href="https://rdrr.io/r/base/names.html" class="external-link">names</a></span><span class="op">(</span><span class="va">df.biv</span><span class="op">)</span><span class="op">[</span><span class="fl">1</span><span class="op">:</span><span class="fl">2</span><span class="op">]</span> <span class="op">&lt;-</span> <span clas