    0     0   0</span></code></pre></div>
<p>The above might be less useful if one would like to get the results by group. In that case, one can provide a grouping vector of names in <code>grouping_cols</code>.</p>
<div class="sourceCode" id="cb16"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span class="va">test</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/structure.html" class="external-link">structure</a></span><span class="op">(</span><span clas