Re: Area Of Triangle



On Jul 9, 5:20 pm, silentsiren1987 <sushant.singh1...@xxxxxxxxx>
wrote:
Hello ,

I am trying to find the triangle with maximum area , from a given set of 'n' integer co-ordinates of the form x,y .
Only problem is 'n' is huge ( of the order of 10^6) so i have to use an efficient method.

So i constructed a convex hull from the given n points. Now i have the vertices of the convex polygon and i need to calculate the area of the maximum triangle.

Is it correct that if i choose any two vertices of the convex hull and then loop over the remaining vertices one by one , every time calculating the area and marking the one with the maximum area , i will get the right answer?
If not please correct me .

thanks

Hi, silentsiren1987:

Yes, that will try all the possibilities,
which increase in number with the cube
of the vertex count on the convex hull.

In a recent thread in this sci.math
newsgroup, the same problem had a
solution which requires checking only
a number of possibilities that rises
with the square of the number of vertices
on the convex hull:

http://groups.google.com/group/sci.math/browse_frm/thread/acb6e5960e4c05c4/86f79e7fc8d02eaa

See the method of solution proposed by
James Waldby there!

regards, chip
.



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