n class="st">"term"</span><span class="op">)</span><span class="op">)</span></span>
<span><span class="va">DT</span> <span class="op">&lt;-</span> <span class="va">DT</span><span class="op">[</span>, <span class="va">.SD</span><span class="op">[</span><span class="fl">1</span><span class="op">]</span>, by <span class="op">=</span> <span class="st">"mcid"</span><span class="op">]</span></span>
<span><span class="va">DT</span></span>
<span><span class="co">#&gt;                  mcid   term   cip6</span></spa