 class="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"center"</span>,<span class="st">"scale"</span><span class="op">)</span><span class="op">)</span></span></span>
<span class="r-wrn co"><span class="r-pr">#&gt;</span> <span class="warning">Warning: </span>These variables have zero variances: WD</span>
<span class="r-in"><span><span class="va">nntrData</span> <span class="op">&lt;-</span> <span class="fu"><