lass="sourceLine" id="cb32-1" data-line-number="1">counts &lt;-<span class="st"> </span><span class="kw"><a href="https://www.rdocumentation.org/packages/base/topics/data.frame">data.frame</a></span>(<span class="dt">x =</span> <span class="kw"><a href="https://www.rdocumentation.org/packages/base/topics/as.Date">as.Date</a></span>(<span class="kw"><a href="https://www.rdocumentation.org/packages/base/topics/c">c</a></span>(<span class="st">'2016-11-21'</span>, <span class="st">'2016-11-23'</span>,  <span c