Diameter
Farthest pair on hull = antipodal pair. Rotate calipers, track distance. Max = diameter.
Advertisement
Width
Minimum distance between two parallel supporting lines. Sweep + minimize.
Advertisement
Min bounding rectangle
Rotate rectangle aligned to hull edges. Minimize area/perimeter. O(N) after hull.
Closest pair of hulls
Sweep both hulls simultaneously. Find min distance between them.