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Related papers: On the Expected Complexity of Random Convex Hulls

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We show that the polyhedron defined as the convex hull of the lattice points above the hyperbola $\left\{xy = n\right\}$ has between $\Omega(n^{1/3})$ and $O(n^{1/3} \log n)$ vertices. The same bounds apply to any hyperbola with rational…

Combinatorics · Mathematics 2025-02-03 David Alcántara , Mónica Blanco , Francisco Criado , Francisco Santos

In this paper we consider the convex hull of a spherically symmetric sample in $R^d$. Our main contributions are some new asymptotic results for the expectation of the number of vertices, number of facets, area and the volume of the convex…

Probability · Mathematics 2014-12-30 Enkelejd Hashorva

In this article, we determine the amortized computational complexity of the planar dynamic convex hull problem by querying. We present a data structure that maintains a set of n points in the plane under the insertion and deletion of points…

Computational Geometry · Computer Science 2019-03-01 Riko Jacob , Gerth Stølting Brodal

Convex hulls are useful as tight bounding proxies for a variety of tasks including collision detection, ray intersection, and distance computation. Unfortunately, the complexity of polyhedral convex hulls grows linearly with their input. We…

Graphics · Computer Science 2026-04-17 Alec Jacobson

We establish an exact formula for the average number of edges appearing on the boundary of the global convex hull of n independent Brownian paths in the plane. This requires the introduction of a counting criterion which amounts to "cutting…

Statistical Mechanics · Physics 2012-12-10 Julien Randon-Furling

For two convex discs $K$ and $L$, we say that $K$ is $L$-convex if it is equal to the intersection of all translates of $L$ that contain $K$. In $L$-convexity the set $L$ plays a similar role as closed half-spaces do in the classical notion…

Metric Geometry · Mathematics 2026-04-09 Ferenc Fodor , Dániel I. Papvári , Viktor Vígh

The random beta polytope is defined as the convex hull of $n$ independent random points with the density proportional to $(1-\|x\|^2)^\beta$ on the $d$-dimensional unit ball, where $\beta>-1$ is a parameter. Similarly, the random beta'…

Probability · Mathematics 2021-07-15 Zakhar Kabluchko

A \emph{thrackle} is a graph drawn in the plane so that every pair of its edges meet exactly once, either at a common end vertex or in a proper crossing. Conway's thrackle conjecture states that the number of edges is at most the number of…

Combinatorics · Mathematics 2023-07-10 Balázs Keszegh , Dániel Simon

The convex hull describes the extent or shape of a set of data and is used ubiquitously in computational geometry. Common algorithms to construct the convex hull on a finite set of n points (x,y) range from O(nlogn) time to O(n) time.…

Computational Geometry · Computer Science 2015-05-06 José O. Cadenas , Graham Megson

A set $S \subset \mathbb{Z}^d$ is digital convex if $conv(S) \cap \mathbb{Z}^d = S$, where $conv(S)$ denotes the convex hull of $S$. In this paper, we consider the algorithmic problem of testing whether a given set $S$ of $n$ lattice points…

Computational Geometry · Computer Science 2019-01-16 Loïc Crombez , Guilherme D. da Fonseca , Yan Gérard

The sample range of uniform random points $X_1, \dots , X_n$ chosen in a given convex set is the convex hull ${\rm conv}[X_1, \dots, X_n]$. It is shown that in dimension three the expected volume of the sample range is not monotone with…

Probability · Mathematics 2016-12-07 Stefan Kunis , Benjamin Reichenwallner , Matthias Reitzner

We prove an explicit combinatorial formula for the expected number of faces of the zero polytope of the homogeneous and isotropic Poisson hyperplane tessellation in $\mathbb R^d$. The expected $f$-vector is expressed through the…

Probability · Mathematics 2020-08-18 Zakhar Kabluchko

We prove that the Random-Edge simplex algorithm requires an expected number of at most 13n/sqrt(d) pivot steps on any simple d-polytope with n vertices. This is the first nontrivial upper bound for general polytopes. We also describe a…

Combinatorics · Mathematics 2008-07-15 Bernd Gärtner , Volker Kaibel

Let $\mu$ be a probability distribution on $\mathbb{R}^d$ which assigns measure zero to every hyperplane and $S$ a set of points sampled independently from $\mu$. What can be said about the expected combinatorial structure of the convex…

Probability · Mathematics 2023-07-13 Brett Leroux

Given a set of $n$ points $P$ in the plane, the first layer $L_1$ of $P$ is formed by the points that appear on $P$'s convex hull. In general, a point belongs to layer $L_i$, if it lies on the convex hull of the set $P \setminus…

Computational Geometry · Computer Science 2017-03-17 Raimi A. Rufai , Dana S. Richards

Given a point set $P$ in the plane, we seek a subset $Q\subseteq P$, whose convex hull gives a smaller and thus simpler representation of the convex hull of $P$. Specifically, let $cost(Q,P)$ denote the Hausdorff distance between the convex…

Computational Geometry · Computer Science 2021-10-05 Georgiy Klimenko , Benjamin Raichel

$\def\DD{{{\bf \delta}}}\def\CH{{\mathop{\mathrm{ConvexHull}}}}\newcommand{\LL}{{\cal {L}}} \newcommand{\ZZ}{\mathbb{Z}} $ Given a convex body $C$ in the plane, its discrete hull is $C^0 = \CH( C \cap \LL )$, where $\LL = \ZZ \times \ZZ$ is…

Computational Geometry · Computer Science 2026-01-05 Sariel Har-Peled

Given a set $P$ of $n$ points in the plane, we study the computation of the probability distribution function of both the area and perimeter of the convex hull of a random subset $S$ of $P$. The random subset $S$ is formed by drawing each…

Computational Geometry · Computer Science 2015-09-10 Pablo Pérez-Lantero

Sometimes, it is possible to represent a complicated polytope as a projection of a much simpler polytope. To quantify this phenomenon, the extension complexity of a polytope $P$ is defined to be the minimum number of facets of a (possibly…

Combinatorics · Mathematics 2022-03-24 Matthew Kwan , Lisa Sauermann , Yufei Zhao

We obtain an upper bound for the volume of the convex hull of a simple closed Frenet curve with exactly four vertices, i.e., four points of vanishing torsion, and lying on the boundary of its convex hull. Moreover, we show that the upper…

Differential Geometry · Mathematics 2026-03-13 Jakob Bohr , Steen Markvorsen , Matteo Raffaelli