f the horizon is simplicial and no merges occur. </p>

<h2><a href="#TOC">&#187;</a><a name="how">How Qhull merges facets</a></h2>

<p>If two facets are not clearly convex, then Qhull removes one
or the other facet by merging the facet into a neighbor. It
selects the merge which minimizes the distance from the
neighboring hyperplane to the facet's vertices. Qhull also
performs merges when a facet has fewer than <i>d</i> neighbors (called a
degenerate facet), when a facet's vertices are included in a
neighbo