 Electricity [from Solar]         6         9</span></span></code></pre></div>
</div>
<div class="section level2">
<h2 id="aggregation-via-dplyrsummarise">Aggregation via <code>dplyr::summarise()</code><a class="anchor" aria-label="anchor" href="#aggregation-via-dplyrsummarise"></a>
</h2>
<p>Another type of aggregation is aided by the metadata columns of a
<code>matsindf</code>-style data frame. With single numbers, an
aggregation might look like this:</p>
<div class="sourceCode" id="cb18"><pre class="downl