Calculate the convex hull of a set of points, i.e. the covering polygon that
has the smallest area.

Usage

convex_hull(data)

Arguments

data

The data points, a numeric matrix with two columns.

Value

A named list with components:

resverts

The indices of the
input vertices that constritute the convex hull.

rescoords

The
coordinates of the corners of the convex hull.

References

Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and
Clifford Stein. Introduction to Algorithms, Second Edition. MIT Press and
McGraw-Hill, 2001. ISBN 0262032937. Pages 949-955 of section 33.3: Finding
the convex hull.