al-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">2</span> <span class="op">)</span></span>
<span><span class="va">Q</span><span class="op">[</span> <span class="fl">1</span><span class="op">:</span><span class="op">(</span><span class="va">I</span><span class="op">/</span><span class="fl">2</span><span class="op">)</span>, <span class="fl">2</span> <span class="op">]</span> <spa