n>distance <span class="op">/</span><span class="st"> </span>(air_time<span class="op">/</span><span class="dv">60</span>)]</span>
<span id="cb16-3"><a href="#cb16-3" aria-hidden="true"></a>  DT[, .(<span class="dt">max_speed =</span> <span class="kw">max</span>(speed)), by =<span class="st"> </span>month]</span>
<span id="cb16-4"><a href="#cb16-4" aria-hidden="true"></a>}</span>
<span id="cb16-5"><a href="#cb16-5" aria-hidden="true"></a>ans =<span class="st"> </span><span class="kw">foo</span>(flights)</sp