t co"><span class="r-pr">#&gt;</span> 13  o  o  o  o</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># data frames unequal in no. of columns</span></span></span>
<span class="r-in"><span><span class="va">df2</span> <span class="op">&lt;-</span> <span class="fu">plyr</span><span class="fu">::</span><span class="fu"><a href="https://rdrr.io/pkg/plyr/man/rdply.html" class="external-link">rdply</a></span><span class="op">(</span><span class="fl">10</span>, <span class="f