Nearest point search

`dsearchn`

is based on Qhull [1]. For information about Qhull, see `http://www.qhull.org/`

. For copyright information,
see `http://www.qhull.org/COPYING.txt`

.

[1] Barber, C.B., D.P. Dobkin, and H.T. Huhdanpaa. “The
Quickhull Algorithm for Convex Hulls.” *ACM Transactions on Mathematical
Software*, Vol. 22, No. 4, Dec. 1996, p 469–483.