|MATLAB Function Reference|
K = convhull(x,y)
returns indices into the
y vectors of the points on the convex hull.
[K,a] = convhull(x,y)
also returns the area of the convex hull.
plot to plot the output of
convhull is based on Qhull . It uses the Qhull joggle option (
'QJ'). For information about
qhull, see http://www.geom.umn.edu/software/qhull/. For copyright information, see http://www.geom.umn.edu/software/download/COPYING.html.
 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. Available in HTML format at http://www.acm.org/ pubs/citations/journals/toms/1996-22-4/p469-barber/ and in PostScript format at ftp://geom.umn.edu/pub/software/qhull-96.ps.
 National Science and Technology Research Center for Computation and Visualization of Geometric Structures (The Geometry Center), University of Minnesota. 1993.