/span><span class="fl">9</span><span class="op">:</span><span class="fl">12</span>,<span class="fl">3</span><span class="op">]</span> <span class="op">&lt;-</span> <span class="fl">1</span></span>
<span></span>
<span><span class="co"># estimate model</span></span>
<span><span class="va">mod1</span> <span class="op">&lt;-</span> <span class="fu">sirt</span><span class="fu">::</span><span class="fu">smirt</span><span class="op">(</span> <span class="va">dat</span>, Qmatrix<span class="op">=</span><span class=