r? if so, first convert</span>
<span class="r-msg co"><span class="r-pr">#&gt;</span>   this variable to a factor using the factor() function</span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/base/class.html" class="external-link">class</a></span><span class="op">(</span><span class="va">seobj</span><span class="op">)</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [1] "DESeqDataSet"</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> attr(,"pa