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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 show that packing axis-aligned unit squares into a simple polygon $P$ is NP-hard, even when $P$ is an orthogonal and orthogonally convex polygon with half-integer coordinates. It has been known since the early 80s that packing unit…

Computational Geometry · Computer Science 2024-04-19 Mikkel Abrahamsen , Jack Stade

The alpha complex is a subset of the Delaunay triangulation and is often used in computational geometry and topology. One of the main drawbacks of using the alpha complex is that it is non-monotone, in the sense that if ${\cal…

Computational Geometry · Computer Science 2021-05-19 Yohai Reani , Omer Bobrowski

In this research paper, the problem of optimization of a quadratic form over the convex hull generated by the corners of hypercube is attempted and solved. It is reasoned that under some conditions, the optimum occurs at the corners of…

Numerical Analysis · Computer Science 2014-01-29 Garimella Rama Murthy

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

In this paper, we consider the polyhedral structure of the unit commitment polytope. In particular, we provide the convex hull results for the problem under the following different settings: 1) the convex hulls for the integrated…

Optimization and Control · Mathematics 2017-02-01 Kai Pan , Yongpei Guan

Convex hulls are fundamental geometric tools used in a number of algorithms. This paper presents a fast, simple to implement and robust Smart Convex Hull (S-CH) algorithm for computing the convex hull of a set of points in E3. This…

Data Structures and Algorithms · Computer Science 2017-08-10 Vaclav Skala , Zuzana Majdisova , Michal Smolik

An incremental approach for computation of convex hull for data points in two-dimensions is presented. The algorithm is not output-sensitive and costs a time that is linear in the size of data points at input. Graham's scan is applied only…

Computational Geometry · Computer Science 2022-02-11 Debashis Mukherjee

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…

Computing mixed volume of convex polytopes is an important problem in computational algebraic geometry. This paper establishes sufficient conditions under which the mixed volume of several convex polytopes exactly equals the normalized…

Algebraic Geometry · Mathematics 2019-02-21 Tianran Chen

A wide range of fundamental machine learning tasks that are addressed by the maximum a posteriori estimation can be reduced to a general minimum conical hull problem. The best-known solution to tackle general minimum conical hull problems…

Machine Learning · Computer Science 2020-08-12 Yuxuan Du , Min-Hsiu Hsieh , Tongliang Liu , Dacheng Tao

This paper presents a new algorithm for the convex hull problem, which is based on a reduction to a combinatorial decision problem POLYTOPE-COMPLETENESS-COMBINATORIAL, which in turn can be solved by a simplicial homology computation. Like…

Metric Geometry · Mathematics 2007-05-23 Michael Joswig , G"unter M. Ziegler

Several results concerning pairs of polynomially convex sets whose union is not even rationally convex are given. It is shown that there is no restriction on how two spaces can be embedded in some $\C^N$ so as to be polynomially convex but…

Complex Variables · Mathematics 2021-08-23 Alexander J. Izzo

We consider polyhedral approximations of strictly convex compacta in finite dimensional Euclidean spaces (such compacta are also uniformly convex). We obtain the best possible estimates for errors of considered approximations in the…

Functional Analysis · Mathematics 2010-10-13 Maxim V. Balashov , Dušan Repovš

Convex sets appear in various mathematical theories, and are used to define notions such as convex functions and hulls. As an abstraction from the usual definition of convex sets in vector spaces, we formalize in Coq an intrinsic…

Logic in Computer Science · Computer Science 2020-05-29 Reynald Affeldt , Jacques Garrigue , Takafumi Saikawa

We show how to construct the nonstandard hull of certain infinite-dimensional Lie algebras in order to generalize a theorem of Pestov on the enlargeability of Banach-Lie algebras. In the process, we consider a nonstandard smoothness…

Differential Geometry · Mathematics 2008-04-04 Isaac Goldbring

With the goal of obtaining strong relaxations for binary polynomial optimization problems, we introduce the pseudo-Boolean polytope defined as the convex hull of the set of binary points satisfying a collection of equations containing…

Optimization and Control · Mathematics 2024-07-02 Alberto Del Pia , Aida Khajavirad

The fundamental geometry of self-similar sets becomes significantly more complex when the generating contractive maps include non-trivial rotational components. A well-known family exemplifying this complexity is that of the dragon curves…

Metric Geometry · Mathematics 2026-01-01 Fan Wen

Generalized polyhedral convex sets, generalized polyhedral convex functions on locally convex Hausdorff topological vector spaces, and the related constructions such as sum of sets, sum of functions, directional derivative, infimal…

Optimization and Control · Mathematics 2017-05-22 Nguyen Ngoc Luan , Jen-Chih Yao , Nguyen Dong Yen

This work uncovers the tropical analogue for measured laminations of the convex hull construction of decorated Teichmueller theory, namely, it is a study in coordinates of geometric degeneration to a point of Thurston's boundary for…

Geometric Topology · Mathematics 2011-06-15 R. C. Penner