">## Turn the tables into a data.frame for testing (convert</span></span></span>
<span class="r-in"><span><span class="co">## the categories variables to numeric with fact2num())</span></span></span>
<span class="r-in"><span><span class="va">df2</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><span class="va">tbl1</span><span class="op">)</span></span></span>
<span class="r-in"><span><s