>
<span class="r-out co"><span class="r-pr">#&gt;</span> [3,] 0.5883484 -5.547002e-01 -0.5883484</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="co"># a positive, semi-definite matrix, with eigenvalues 12, 6, 0</span></span></span>
<span class="r-in"><span><span class="va">C</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="fu"><a href="https://rd