"fl">0</span><span class="op">)</span> <span class="op">)</span></span>
<span><span class="co"># set the covariance between the first and second dimension to zero</span></span>
<span><span class="va">mod8</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="va">Q</span>, irtmodel<span class="op">=</span><span class="st">"comp"</span>, variance.f