I think we were (at least I was) not so much interested in the number of
points of the polygon (vertices), as well as the number of points to be
examined, which was huge: "there are very few polygons but a gazillion
points" http://jsoftware.com/pipermail/programming/2010-April/019248.html 


R.E. Boss


> -----Oorspronkelijk bericht-----
> Van: [email protected] [mailto:programming-
> [email protected]] Namens Henry Rich
> Verzonden: donderdag 22 april 2010 3:55
> Aan: Programming forum
> Onderwerp: Re: [Jprogramming] Polygon containment
> 
> Did Boyko answer this sufficiently?  You don't have to examine each point.
> 
> One way to think of a convex polygon is that the vertices are sorted (in
> angular order), so the parallel is close.
> 
> Henry Rich
> 
> Roger Hui wrote:
> > I don't think it's possible to "do a convex polygon"
> > (or to do most anything) in O(log n) time.  Simply to
> > examine each point requires O(n) time.
> >
> > You can do binary search in O(log n) time, but
> > that assumes that the points are sorted.
> >


----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to