</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/factor.html" class="external-link">factor</a></span><span class="op">(</span><span class="va">id</span><span class="op">)</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co">################################################</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="va">fm1</span> <span class="op">&lt;-</span> <span c