# Finding the convex hull of a set of points

• 05-16-2013, 12:06 PM
jenny_wui
Finding the convex hull of a set of points
Hello every body, I need to find the convex hull of a set of points. Could any one help me how that can be done. Lastly, I need to find the boundary of the convex hull. Thanks.
• 05-16-2013, 02:45 PM
Carmine
The convex hull of a set of points (call it P) in a plane would be made up of line segments connecting some of the points in P. The convex hull of a set of points in 3-space (call it Q) would be made up of a set of triangles with vertices from Q. Do you have a 2D or 3D situation? Have you tried Googling 'Convex Hull'? I believe there's some free code you can get to do hulls. I think QHull is one of them.

Note: I'm not defining 'Convex Hull' in the statements above. I'm just describing what the geometric boundaries of 2D or 3D hulls would be.
• 05-16-2013, 04:14 PM
jenny_wui
I need to find convex hull in 2D. Actually I am looking for some relevant code in the net. Thanks.
• 05-17-2013, 10:20 AM
Carmine
2D is fairly straightforward. Maybe after reading overviews of some of the algorithms you can write it yourself? For 2D I suggest the gift wrapping approach. For 3D, I like the incremental approach.
• 05-20-2013, 12:36 PM
jenny_wui
Thanks, a nice implementation has been given to the following link:
http://en.wikibooks.org/wiki/Algorit...Monotone_chain