<a href="https://rdrr.io/r/base/levels.html" class="external-link">levels</a></span><span class="op">(</span><span class="va">Skulls</span><span class="op">$</span><span class="va">epoch</span><span class="op">)</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># longer variable labels</span></span></span>
<span class="r-in"><span><span class="va">vlab</span> <span class="op">&lt;-</span> <span class="fu">