n class="op">&lt;-</span> <span class="fu"><a href="https://amices.org/mice/reference/cbind.html" class="external-link">cbind</a></span><span class="op">(</span> <span class="va">theta.k</span><span class="op">[</span>,<span class="fl">1</span><span class="op">]</span>, <span class="va">theta.k</span><span class="op">[</span>,<span class="fl">1</span><span class="op">]</span><span class="op">^</span><span class="fl">2</span> <span class="op">)</span></span>
<span><span class="co"># define Q-matrix</span></s