#### CSC274b

Spring 1998

Ileana Streinu

#
Lecture 13

#### Monday, March 2, 1998

#### Convex Hulls in dimension 2

- Analogy:
Sorting Algorithms
. Another Java applet for
sorting algorithms, convex hull et al..
- Animated Algorithms (sorting, convex hulls, etc.) on the Web:
- Textbook: Chapter 3, page 70.
- Why convex hulls? Applications: moving robot through
obstacles: it is easier to do computations of collision avoidance
for convex objects (robot, obstacles).
- Definition of convex hull and convexity.
- Extreme points. Computing extreme points versus computing
convex hulls.
- Naive algorithms: non-extreme points; extreme edges.
- Gift Wrapping (
Jarvis' March
): O(n^2) (or, rather, O(nh)).

Last modified March 2, 1998.