e r">
<code class="sourceCode R"><span class="fu"><a href="https://rdrr.io/r/utils/head.html" class="external-link">head</a></span><span class="op">(</span><span class="fu"><a href="reference/custom_na_recode.html">custom_na_recode</a></span><span class="op">(</span><span class="va">airquality</span><span class="op">)</span><span class="op">)</span>
<span class="co">#&gt;      Ozone  Solar.R Wind Temp Month Day</span>
<span class="co">#&gt; 1 41.00000 190.0000  7.4   67     5   1</span>
<span class="co">#&g