MATLAB Functions

Convex hull

K = convhull(x,y)
K = convhull(x,y,TRI)

K = convhull(x,y)

returns indices into the x and y vectors of the points on the convex hull.

K = convhull(x,y,TRI)

uses the triangulation (as obtained from delaunay) instead of computing it each time.

xx = -1:.05:1; yy = abs(sqrt(xx));
[x,y] = pol2cart(xx,yy);
k = convhull(x,y);
plot(x(k),y(k),'r-',x,y,'b+')