### 11.10.5 Convex hulls: convexhull

The convexhull command uses the Graham scanning algorithm to find the convex hull of a set of points.

convexhull takes as argument a list of points.

convexhull returns the vertices of the convex hull of the points.
Input:

convexhull(0,1,1+i,1+2i,-1-i,1-3i,-2+i)

Output:

(1-3*i,1+2*i,-2+i,-1-i)

To draw the hull, use the polygon command with the output of convexhull.
Input:

polygon(convexhull(0,1,1+i,1+2i,-1-i,1-3i,-2+i))

Output: