n>)</span>
<span id="cb14-2"><a href="#cb14-2" aria-hidden="true"></a>out_cols =<span class="st"> </span><span class="kw">c</span>(<span class="st">&quot;max_dep_delay&quot;</span>, <span class="st">&quot;max_arr_delay&quot;</span>)</span>
<span id="cb14-3"><a href="#cb14-3" aria-hidden="true"></a>flights[, <span class="kw">c</span>(out_cols) <span class="op">:</span><span class="er">=</span><span class="st"> </span><span class="kw">lapply</span>(.SD, max), by =<span class="st"> </span>month, .SDcols =<span