">1</span><span class="op">:</span><span class="fu"><a href="https://rdrr.io/r/base/dim.html">dim</a></span><span class="op">(</span><span class="va">X1</span><span class="op">)</span><span class="op">[</span><span class="fl">2</span><span class="op">]</span><span class="op">)</span>, trace <span class="op">=</span> <span class="cn">FALSE</span><span class="op">)</span>

<span class="co"># Three-fold CV, horizontal</span>
<span class="va">lp.cv3</span> <span class="op">&lt;-</span> <span class="fu"><a href=