
<span class="r-in"><span>  <span class="kw">if</span><span class="op">(</span><span class="op">!</span><span class="fu"><a href="https://rdrr.io/r/base/numeric.html" class="external-link">is.numeric</a></span><span class="op">(</span><span class="va">y</span><span class="op">)</span><span class="op">)</span><span class="op">{</span></span></span>
<span class="r-in"><span>    <span class="kw"><a href="https://rdrr.io/r/base/stop.html" class="external-link">stop</a></span><span class="op">(</span><span class