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Related papers: Counting Triangulations of Configurations

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Counting Euclidean triangulations with vertices in a finite set $\C$ of the convex hull $\conv(\C)$ of $\C$ is difficult in general, both algorithmically and theoretically. The aim of this paper is to describe nearly convex polygons, a…

Combinatorics · Mathematics 2010-12-13 Roland Bacher , Frédéric Mouton

The triangulations of a regular convex polygon are enumerated according to the number of diagonals parallel to a fixed edge. The enumeration uses the Shapiro convolution identity, as well as an interpretation of this identity in terms of…

Combinatorics · Mathematics 2012-08-21 Alon Regev

We compute the number of triangulations of a convex $k$-gon each of whose sides is subdivided by $r-1$ points. We find explicit formulas and generating functions, and we determine the asymptotic behaviour of these numbers as $k$ and/or $r$…

Combinatorics · Mathematics 2017-02-06 Andrei Asinowski , Christian Krattenthaler , Toufik Mansour

In this paper, we obtain the counting formulaes of convex pentagons and convex hexagons, respectively, in an $n$-triangular net by solving the corresponding recursive formulaes.

Combinatorics · Mathematics 2010-12-21 Jun-Ming Zhu

We describe a new algorithm to compute the geometric intersection number between two curves, given as edge vectors on an ideal triangulation. Most importantly, this algorithm runs in polynomial time in the bit-size of the two edge vectors.…

Geometric Topology · Mathematics 2016-05-12 Mark C. Bell , Richard C. H. Webb

We describe an efficient algorithm to compute a pseudotriangulation of a finite planar family of pairwise disjoint convex bodies presented by its chirotope. The design of the algorithm relies on a deepening of the theory of visibility…

Computational Geometry · Computer Science 2012-08-14 Luc Habert , Michel Pocchiola

In this work we count the number of satisfying states of triangulations of a convex n-gon using the transfer matrix method. We show an exponential (in n) lower bound. We also give the exact formula for the number of satisfying states of a…

Combinatorics · Mathematics 2009-12-18 Andrea Jiménez , Marcos Kiwi , Martin Loebl

We give upper and lower bounds on the maximum and minimum number of geometric configurations of various kinds present (as subgraphs) in a triangulation of $n$ points in the plane. Configurations of interest include \emph{convex polygons},…

Combinatorics · Mathematics 2015-09-22 Adrian Dumitrescu , Maarten Löffler , André Schulz , Csaba D. Tóth

Rectangulations are decompositions of a square into finitely many axis-aligned rectangles. We describe realizations of $(n-1)$-dimensional polytopes associated with two combinatorial families of rectangulations composed of $n$ rectangles.…

Combinatorics · Mathematics 2025-06-30 Jean Cardinal , Vincent Pilaud

A pseudo-triangle is a simple polygon with three convex vertices, and a pseudo-triangulation is a face-to-face tiling of a planar region into pseudo-triangles. Pseudo-triangulations appear as data structures in computational geometry, as…

Combinatorics · Mathematics 2015-02-18 Guenter Rote , Francisco Santos , Ileana Streinu

The intersection matrix of a simplicial complex has entries equal to the rank of the intersection of its facets. In [1] the authors prove the intersection matrix is enough to determine a triangulation of a surface up to isomorphism. In this…

Geometric Topology · Mathematics 2021-03-01 Jorge L. Arocha , Jorge Fernández-Hidalgo

Delaunay triangulations of a point set in the Euclidean plane are ubiquitous in a number of computational sciences, including computational geometry. Delaunay triangulations are not well defined as soon as 4 or more points are concyclic but…

Computational Geometry · Computer Science 2018-04-05 Vincent Despré , Olivier Devillers , Hugo Parlier , Jean-Marc Schlenker

Given a surface with boundary and some points on its boundary, a polygon diagram is a way to connect those points as vertices of non-overlapping polygons on the surface. Such polygon diagrams represent non-crossing permutations on a surface…

Combinatorics · Mathematics 2019-09-27 Norman Do , Jian He , Daniel V. Mathews

We introduce a notion of $k$-convexity and explore polygons in the plane that have this property. Polygons which are \mbox{$k$-convex} can be triangulated with fast yet simple algorithms. However, recognizing them in general is a 3SUM-hard…

Computational Geometry · Computer Science 2010-07-22 Oswin Aichholzer , Franz Aurenhammer , Erik D. Demaine , Ferran Hurtado , Pedro Ramos , Jorge Urrutia

Chirotopes are a common combinatorial abstraction of (planar) point sets. In this paper we investigate decomposition methods for chirotopes, and their application to the problem of counting the number of triangulations supported by a given…

Computational Geometry · Computer Science 2026-03-12 Mathilde Bouvel , Valentin Féray , Xavier Goaoc , Florent Koechlin

We study the set of image tuples arising from fixed cameras observing varying planar 3-dimensional point configurations. We derive a formula for the number of complex critical points of the triangulation problem, which seeks to reconstruct…

Algebraic Geometry · Mathematics 2026-05-01 Petr Hrubý , Elima Shehu

We present a, hopefully, elementary mathematical treatment of the computational aspects of congruent numbers, such that an amateur could understand the problem and perform their own calculations.

Number Theory · Mathematics 2021-03-04 Allan J. MacLeod

3-manifolds are commonly represented as triangulations, consisting of abstract tetrahedra whose triangular faces are identified in pairs. The combinatorial sparsity of a triangulation, as measured by the treewidth of its dual graph, plays a…

Computational Geometry · Computer Science 2026-03-13 Kristóf Huszár , Clément Maria

A fixed set of vertices in the plane may have multiple planar straight-line triangulations in which the degree of each vertex is the same. As such, the degree information does not completely determine the triangulation. We show that even if…

Computational Complexity · Computer Science 2025-10-07 Erin Chambers , Tim Ophelders , Anna Schenfisch , Julia Sollberger

Polytope numbers for a polytope are a sequence of nonnegative integers that are defined by the facial information of a polytope. Every polygon is triangulable and a higher dimensional analogue of this fact states that every polytope is…

Combinatorics · Mathematics 2012-06-05 H. K. Kim , J. Y. Lee
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