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Let $P$ be a set of $n$ points in the plane. We consider a variation of the classical Erd\H{o}s-Szekeres problem, presenting efficient algorithms with $O(n^3)$ running time and $O(n^2)$ space complexity that compute: (1) A subset $S$ of $P$…

Computational Geometry · Computer Science 2024-12-18 Hernán González-Aguilar , David Orden , Pablo Pérez-Lantero , David Rappaport , Carlos Seara , Javier Tejel , Jorge Urrutia

A convex partition of a point set P in the plane is a planar partition of the convex hull of P with empty convex polygons or internal faces whose extreme points belong to P. In a convex partition, the union of the internal faces give the…

Computational Geometry · Computer Science 2020-12-16 Hadrien Cambazard , Nicolas Catusse

Let $P$ be a simple polygon with $n$ vertices, and let $A$ be a set of $m$ points or line segments inside $P$. We develop data structures that can efficiently count the number of objects from $A$ that are visible to a query point or a query…

Computational Geometry · Computer Science 2022-01-11 Kevin Buchin , Bram Custers , Ivor van der Hoog , Maarten Löffler , Aleksandr Popov , Marcel Roeloffzen , Frank Staals

Let $s$ be a point in a polygonal domain $\mathcal{P}$ of $h-1$ holes and $n$ vertices. We consider a quickest visibility query problem. Given a query point $q$ in $\mathcal{P}$, the goal is to find a shortest path in $\mathcal{P}$ to move…

Computational Geometry · Computer Science 2017-03-10 Haitao Wang

Prune-and-search is an important paradigm for solving many important geometric problems. We show that the general prune-and-search technique can be implemented where the objects are given in read-only memory. As examples we consider…

Computational Geometry · Computer Science 2012-12-24 Minati De , Subhas C. Nandy , Sasanka Roy

We consider the problem of minimizing a convex function over a convex set given access only to an evaluation oracle for the function and a membership oracle for the set. We give a simple algorithm which solves this problem with…

Data Structures and Algorithms · Computer Science 2017-06-23 Yin Tat Lee , Aaron Sidford , Santosh S. Vempala

Let $P$ be a set of $n$ points in general position on the plane. A set of closed convex polygons with vertices in $P$, and with pairwise disjoint interiors is called a convex decomposition of $P$ if their union is the convex hull of $P$,…

Combinatorics · Mathematics 2019-09-16 Toshinori Sakai , Jorge Urrutia

We present self-adjusting data structures for answering point location queries in convex and connected subdivisions. Let $n$ be the number of vertices in a convex or connected subdivision. Our structures use $O(n)$ space. For any convex…

Computational Geometry · Computer Science 2018-10-02 Siu-Wing Cheng , Man-Kit Lau

We present a mathematical and algorithmic scheme for learning the principal geometric elements in an image or 3D object. We build on recent work that convexifies the basic problem of finding a combination of a small number shapes that…

Computer Vision and Pattern Recognition · Computer Science 2016-07-05 Alireza Aghasi , Justin Romberg

Computing the convex hull of a planar $n$-point set $P$ is one of the most fundamental problems in computational geometry. It has an $\Omega(n \log n)$ lower bound in the algebraic computation tree model, and many convex hull algorithms…

In this work, we consider bilevel optimization when the lower-level problem is strongly convex. Recent works show that with a Hessian-vector product (HVP) oracle, one can provably find an $\epsilon$-stationary point within…

Optimization and Control · Mathematics 2026-05-26 Lesi Chen , Yaohua Ma , Jingzhao Zhang

We show that learning a convex body in $\RR^d$, given random samples from the body, requires $2^{\Omega(\sqrt{d/\eps})}$ samples. By learning a convex body we mean finding a set having at most $\eps$ relative symmetric difference with the…

Machine Learning · Computer Science 2009-04-09 Navin Goyal , Luis Rademacher

Let $P$ be a planar set of $n$ points in general position. We consider the problem of computing an orientation of the plane for which the Rectilinear Convex Hull of $P$ has minimum area. Bae et al. (Computational Geometry: Theory and…

Computational Geometry · Computer Science 2017-12-29 Carlos Alegría-Galicia , Tzolkin Garduño , Carlos Seara , Areli Rosas-Navarrete , Jorge Urrutia

We study to what extent quantum algorithms can speed up solving convex optimization problems. Following the classical literature we assume access to a convex set via various oracles, and we examine the efficiency of reductions between the…

Quantum Physics · Physics 2020-01-15 Joran van Apeldoorn , András Gilyén , Sander Gribling , Ronald de Wolf

This study presents a novel algorithm for identifying the set of extreme points that constitute the exact convex hull of a point set in high-dimensional Euclidean space. The proposed method iteratively solves a sequence of dynamically…

Computational Geometry · Computer Science 2025-11-11 Qianwei Zhuang

We explore the separability of point sets in the plane by a restricted-orientation convex hull, which is an orientation-dependent, possibly disconnected, and non-convex enclosing shape that generalizes the convex hull. Let $R$ and $B$ be…

Computational Geometry · Computer Science 2022-09-12 Carlos Alegría , David Orden , Carlos Seara , Jorge Urrutia

Consider a dataset of vector-valued observations that consists of noisy inliers, which are explained well by a low-dimensional subspace, along with some number of outliers. This work describes a convex optimization problem, called REAPER,…

Information Theory · Computer Science 2015-07-24 Gilad Lerman , Michael McCoy , Joel A. Tropp , Teng Zhang

In this work, we present a new efficient method for convex shape representation, which is regardless of the dimension of the concerned objects, using level-set approaches. Convexity prior is very useful for object completion in computer…

Computer Vision and Pattern Recognition · Computer Science 2020-03-24 Lingfeng li , Shousheng Luo , Xue-Cheng Tai , Jiang Yang

We study the problem of chasing convex bodies online: given a sequence of convex bodies $K_t\subseteq \mathbb{R}^d$ the algorithm must respond with points $x_t\in K_t$ in an online fashion (i.e., $x_t$ is chosen before $K_{t+1}$ is…

Data Structures and Algorithms · Computer Science 2020-01-08 C. J. Argue , Anupam Gupta , Guru Guruganesh , Ziye Tang

Let $X$ be a set of points in $\mathbb{R}^2$ and $\mathcal{O}$ be a set of geometric objects in $\mathbb{R}^2$, where $|X| + |\mathcal{O}| = n$. We study the problem of computing a minimum subset $\mathcal{O}^* \subseteq \mathcal{O}$ that…

Computational Geometry · Computer Science 2024-03-04 Timothy M. Chan , Qizheng He , Jie Xue