an class="st">"wind_speed"</span><span class="op">)</span></span></code></pre></div>
<pre><code><span><span class="co">## Aggregation function missing: defaulting to length</span></span></code></pre>
<div class="sourceCode" id="cb10"><pre class="downlit sourceCode r">
<code class="sourceCode R"><span><span class="va">flights.grp</span><span class="op">[[</span><span class="st">"wind_speed"</span><span class="op">]</span><span class="op">]</span> <span class="op">&lt;-</span> <span class="va">weather_wind_sp