pan class="co"># Model 5: Unidimensional 1PL model</span></span>
<span><span class="va">Qmatrix</span> <span class="op">&lt;-</span> <span class="fu"><a href="https://rdrr.io/r/base/matrix.html" class="external-link">matrix</a></span><span class="op">(</span> <span class="fl">1</span>, nrow<span class="op">=</span><span class="va">I</span>, ncol<span class="op">=</span><span class="fl">1</span> <span class="op">)</span></span>
<span><span class="va">mod5</span> <span class="op">&lt;-</span> <span class="fu"