English
Related papers

Related papers: Finding a largest empty convex subset in space is …

200 papers

An empty pentagon in a point set P in the plane is a set of five points in P in strictly convex position with no other point of P in their convex hull. We prove that every finite set of at least 328k^2 points in the plane contains an empty…

A set is star-shaped if there is a point in the set that can see every other point in the set in the sense that the line-segment connecting the points lies within the set. We show that testing whether a non-empty compact smooth region is…

Computational Geometry · Computer Science 2025-11-20 Marcus Schaefer , Daniel Štefankovič

A planar point set is in convex position precisely when it has a convex polygonization, that is, a polygonization with maximum interior angle measure at most \pi. We can thus talk about the convexity of a set of points in terms of the…

Computational Geometry · Computer Science 2014-09-16 Danny Rorabaugh

We give an overview of the 2020 Computational Geometry Challenge, which targeted the problem of partitioning the convex hull of a given planar point set P into the smallest number of convex faces, such that no point of P is contained in the…

Computational Geometry · Computer Science 2020-04-10 Erik D. Demaine , Sándor P. Fekete , Phillip Keldenich , Dominik Krupke , Joseph S. B. Mitchell

In the convex covering problem, we are given a convex polygon with holes $P$ and the goal is to cover $P$ using a small number of convex polygons that lie inside $P$. In this paper, we solve the problem using the following strategy. We find…

Computational Geometry · Computer Science 2025-06-23 Guilherme D. da Fonseca

We consider the computational versions of the Erd\H os-Szekeres theorem and related problems in 3 dimensions. We show that, in constrast to the planar case, no polynomial time algorithm exists for determining the largest (empty) convex…

Computational Geometry · Computer Science 2011-11-28 Christian Knauer , Daniel Werner

Consider a set $P \subseteq \Re^d$ of $n$ points, and a convex body $C$ provided via a separation oracle. The task at hand is to decide for each point of $P$ if it is in $C$ using the fewest number of oracle queries. We show that one can…

Computational Geometry · Computer Science 2021-04-02 Sariel Har-Peled , Mitchell Jones , Saladi Rahul

Discrepancy measures how uniformly distributed a point set is with respect to a given set of ranges. There are two notions of discrepancy, namely continuous discrepancy and combinatorial discrepancy. Depending on the ranges, several…

Computational Geometry · Computer Science 2011-03-24 Panos Giannopoulos , Christian Knauer , Magnus Wahlström , Daniel Werner

We consider the following geometric optimization problem: find a maximum-area rectangle and a maximum-perimeter rectangle contained in a given convex polygon with $n$ vertices. We give exact algorithms that solve these problems in time…

Computational Geometry · Computer Science 2014-10-08 Sergio Cabello , Otfried Cheong , Christian Knauer , Lena Schlipf

A new algorithm for the determination of the relative convex hull in the plane of a simple polygon A with respect to another simple polygon B which contains A, is proposed. The relative convex hull is also known as geodesic convex hull, and…

Computational Geometry · Computer Science 2016-05-02 P. Wiederhold , H. Reyes

In this paper we consider the problem of minimizing area subject to a volume constraint in a given convex set.

Analysis of PDEs · Mathematics 2007-05-23 Edward Stredulinsky , William P. Ziemer

In this paper the problem of maximizing the distance to a given fixed point over an intersection of balls is considered. It is known that this problem is NP complete in the general case, since any subset sum problem can be solved upon…

Optimization and Control · Mathematics 2023-07-26 Marius Costandin

For a finite point set $P \subset \mathbb{R}^d$, denote by $\text{diam}(P)$ the ratio of the largest to the smallest distances between pairs of points in $P$. Let $c_{d, \alpha}(n)$ be the largest integer $c$ such that any $n$-point set $P…

Combinatorics · Mathematics 2025-01-30 Boris Bukh , Zichao Dong

We give a construction of a convex set $A \subset \mathbb R$ with cardinality $n$ such that $A-A$ contains a convex subset with cardinality $\Omega (n^2)$. We also consider the following variant of this problem: given a convex set $A$, what…

Combinatorics · Mathematics 2023-09-15 Krishnendu Bhowmick , Ben Lund , Oliver Roche-Newton

We consider the problem of wrapping three-dimensional solid bodies with a given planar sheet of paper, where the paper may be folded or wrinkled but not stretched or torn. We propose a conjecture characterising the maximumvolume solid…

Metric Geometry · Mathematics 2026-04-06 R Nandakumar

We study the $O_\beta$-hull of a planar point set, a generalization of the Orthogonal Convex Hull where the coordinate axes form an angle $\beta$. Given a set $P$ of $n$ points in the plane, we show how to maintain the $O_\beta$-hull of $P$…

Computational Geometry · Computer Science 2018-11-19 Carlos Alegría-Galicia , David Orden , Carlos Seara , Jorge Urrutia

We study the problem of discrete geometric packing. Here, given weighted regions (say in the plane) and points (with capacities), one has to pick a maximum weight subset of the regions such that no point is covered more than its capacity.…

Computational Geometry · Computer Science 2011-12-01 Alina Ene , Sariel Har-Peled , Benjamin Raichel

We give an overview of the 2024 Computational Geometry Challenge targeting the problem \textsc{Maximum Polygon Packing}: Given a convex region $P$ in the plane, and a collection of simple polygons $Q_1, \ldots, Q_n$, each $Q_i$ with a…

Computational Geometry · Computer Science 2024-03-26 Sándor P. Fekete , Phillip Keldenich , Dominik Krupke , Stefan Schirra

The present work concerns generalized convex sets in the real multi-dimensional Euclidean space, known as weakly $1$-convex and weakly $1$-semiconvex sets. An open set is called weakly $1$-convex (weakly $1$-semiconvex) if, through every…

General Topology · Mathematics 2024-12-03 Tetiana M. Osipchuk

Many years ago John Tyrell a lecturer at King's college London challenged his Ph.D. students with the following puzzle: show that there is a unique triangle of minimal perimeter with exactly one vertex to lie on one of three given lines,…

Optimization and Control · Mathematics 2026-01-21 Triloki Nath , Manohar Choudhary , Ram K. Pandey