va">N</span>      <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/dim.html" class="external-link">dim</a></span><span class="op">(</span><span class="va">ydata</span><span class="op">)</span><span class="op">[</span><span class="fl">1</span><span class="op">]</span></span></span>
<span class="r-in"><span><span class="va">ycovar</span> <span class="op">&lt;-</span> <span class="va">ydata</span><span class="op">*</span><span class="fl">0</span> <span class="op">+</span> <span cl