Sets of Points with Many Halving Lines

نویسنده

  • David Eppstein
چکیده

We used a genetic search algorithm to find sets of points with many halving lines. There are sets of 10 points with 13 halving lines, 12 points with 18 halving lines, 14 points with 22 halving lines, 16 points with 27 halving lines, and 18 points with 32 halving lines. We find a construction generalizing the 12 point configuration and show that, for any n = 3 · 2, there are configurations of n points with n log4(2n/3) = 3(i+ 1)2i−1 halving lines. Figure 1. (a) 4 points, 3 halving lines; (b) 6 points, 6 halving lines.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Dense point sets with many halving lines

We construct a dense point set of n points in the plane with ne( √ logn) halving lines. This improves the bound O(n log n) of Edelsbrunner, Valtr and Welzl from 1997. We also observe that the upper bound on the maximum number of halving lines of dense point set can be improved to O(n). Our construction can be generalized to higher dimensions, for any d we construct a dense point set of n points...

متن کامل

On $(\le k)$-edges, crossings, and halving lines of geometric drawings of Kn

Let P be a set of points in general position in the plane. Join all pairs of points in P with straight line segments. The number of segment-crossings in such a drawing, denoted by cr(P ), is the rectilinear crossing number of P . A halving line of P is a line passing though two points of P that divides the rest of the points of P in (almost) half. The number of halving lines of P is denoted by ...

متن کامل

Recent developments on the number of ( ≤ k ) - sets , halving lines , and the rectilinear crossing number of Kn . Bernardo

We present the latest developments on the number of (≤ k)-sets and halving lines for (generalized) configurations of points; as well as the rectilinear and pseudolinear crossing numbers of Kn. In particular, we define perfect generalized configurations on n points as those whose number of (≤ k)-sets is exactly 3¡k+1 2 ¢ for all k ≤ n/3. We conjecture that for each n there is a perfect configura...

متن کامل

Halving Point Sets

Given n points in R d , a hyperplane is called halving if it has at most bn=2c points on either side. How many partitions of a point set (into the points on one side, on the hyperplane, and on the other side) by halving hyperplanes can be realized by an n-point set in R d ? Consider the following algorithmic problem rst. Given n points in R d , we want to nd a hyperplane that minimizes the sum ...

متن کامل

Halving Lines and Their Underlying Graphs

In this paper we study underlying graphs corresponding to a set of halving lines. We establish many properties of such graphs. In addition, we tighten the upper bound for the number of halving lines.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 1992