nearly singular computations. When a
determinant is nearly singular, he uses exact arithmetic to
compute a precise result.</p>

<h2><a href="#TOC">&#187;</a><a name="approximate">Approximating a
convex hull</a></h2>

<p>Qhull may be used for approximating a convex hull. This is
particularly valuable in 5-d and higher where hulls can be
immense. You can use '<a href="qh-optq.htm#Qx">Qx</a> <a
href="qh-optc.htm#Cn">C-n</a>' to merge facets as the hull is
being constructed. Then use '<a href="qh-optc.htm#Cn2">