" class="external-link">c</a></span><span class="op">(</span><span class="fl">2</span>, <span class="fl">4</span>, <span class="fl">6</span><span class="op">)</span><span class="op">]</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="fu"><a href="https://rdrr.io/r/graphics/plot.default.html" class="external-link">plot</a></span><span class="op">(</span><span class="va">us_monthly</span><span class="op">$</span><span class="va">date</span>, <span class="va">us