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Topic: How to find a bounding line?
Replies: 39   Last Post: Jul 12, 2013 5:39 AM

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 Peter Percival Posts: 2,623 Registered: 10/25/10
Re: How to find a bounding line?
Posted: Jul 8, 2013 7:18 AM

ols6000@sbcglobal.net wrote:
> I have a N points (x_i, y_i). I want to find a bounding line y = ax + b, such that y_i - y(x_i) >= 0. x_i and y_i are positive integers; a, b and y are real,and x is an integer.
>
> y_i = i, and x_{i+1} > x_i for all i<N
>
> N is very large (100,000 - 1,000,000), so I'm looking for a method that is O(N) (or better).
>
> An ideas on how this line could be found, i e, how to determine a and b efficiently from the N data points?

If this can be restated as a 'find the convex hull of a finite set of
points' problem, then the references here:
https://en.wikipedia.org/wiki/Convex_hull_algorithms may be relevant.

--
I think I am an Elephant,
Behind another Elephant
Behind /another/ Elephant who isn't really there....
A.A. Milne

Date Subject Author
7/7/13 Woody
7/7/13 Scott Berg
7/7/13 Peter Percival
7/7/13 Woody
7/7/13 quasi
7/7/13 quasi
7/8/13 quasi
7/8/13 Woody
7/8/13 quasi
7/8/13 LudovicoVan
7/8/13 LudovicoVan
7/10/13 Woody
7/10/13 quasi
7/8/13 Leon Aigret
7/8/13 Woody
7/10/13 Leon Aigret
7/10/13 Leon Aigret
7/10/13 Woody
7/10/13 RGVickson@shaw.ca
7/10/13 Woody
7/10/13 quasi
7/7/13 quasi
7/7/13 quasi
7/7/13 quasi
7/8/13 William Elliot
7/8/13 Peter Percival
7/8/13 quasi
7/11/13 Woody
7/11/13 quasi
7/11/13 LudovicoVan
7/11/13 quasi
7/11/13 Leon Aigret
7/11/13 Woody
7/11/13 Leon Aigret
7/12/13 Woody
7/12/13 Leon Aigret
7/11/13 Woody
7/12/13 quasi
7/12/13 Woody
7/12/13 quasi