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Related papers: Upright-Quad Drawing of st-Planar Learning Spaces

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In this paper, we introduce tiled graphs as models of learning and maturing processes. We show how tiled graphs can combine graphs of learning spaces or antimatroids (partial hypercubes) and maturity models (total orders) to yield models of…

Discrete Mathematics · Computer Science 2024-03-05 Špela Kajzer , Alexander Dobler , Janja Jerebic , Martin Nöllenburg , Joachim Orthaber , Drago Bokal

We study the classic graph drawing problem of drawing a planar graph using straight-line edges with a prescribed convex polygon as the outer face. Unlike previous algorithms for this problem, which may produce drawings with exponential…

Computational Geometry · Computer Science 2012-03-01 Erin W. Chambers , David Eppstein , Michael T. Goodrich , Maarten Löffler

Canonical orderings serve as the basis for many incremental planar drawing algorithms. All these techniques, however, have in common that they are limited to undirected graphs. While $st$-orderings do extend to directed graphs, especially…

Data Structures and Algorithms · Computer Science 2016-08-31 Martin Gronemann

A well-known result by Kant [Algorithmica, 1996] implies that n-vertex outerplane graphs admit embedding-preserving planar straight-line grid drawings where the internal faces are convex polygons in $O(n^2)$ area. In this paper, we present…

Computational Geometry · Computer Science 2025-08-28 Michael A. Bekos , Giordano Da Lozzo , Fabrizio Frati , Giuseppe Liotta , Antonios Symvonis

A planar orthogonal drawing of a planar 4-graph G (i.e., a planar graph with vertex-degree at most four) is a crossing-free drawing that maps each vertex of G to a distinct point of the plane and each edge of $G$ to a sequence of horizontal…

Computational Geometry · Computer Science 2022-05-17 Walter Didimo , Michael Kaufmann , Giuseppe Liotta , Giacomo Ortali

We study planar drawings of directed graphs in the L-drawing standard. We provide necessary conditions for the existence of these drawings and show that testing for the existence of a planar L-drawing is an NP-complete problem. Motivated by…

While orthogonal drawings have a long history, smooth orthogonal drawings have been introduced only recently. So far, only planar drawings or drawings with an arbitrary number of crossings per edge have been studied. Recently, a lot of…

We describe algorithms for drawing media, systems of states, tokens and actions that have state transition graphs in the form of partial cubes. Our algorithms are based on two principles: embedding the state transition graph in a…

Data Structures and Algorithms · Computer Science 2007-05-23 David Eppstein

The goal of subspace learning is to find a $k$-dimensional subspace of $\mathbb{R}^d$, such that the expected squared distance between instance vectors and the subspace is as small as possible. In this paper we study subspace learning in a…

Machine Learning · Computer Science 2016-05-27 Alon Gonen , Dan Rosenbaum , Yonina Eldar , Shai Shalev-Shwartz

Matrix Factorization has emerged as a widely adopted framework for modeling data exhibiting low-rank structures. To address challenges in manifold learning, this paper presents a subspace-constrained quadratic matrix factorization model.…

Machine Learning · Computer Science 2024-11-08 Zheng Zhai , Xiaohui Li

In a planar confluent orthogonal drawing (PCOD) of a directed graph (digraph) vertices are drawn as points in the plane and edges as orthogonal polylines starting with a vertical segment and ending with a horizontal segment. Edges may…

Computational Geometry · Computer Science 2022-09-01 Sabine Cornelsen , Gregor Diatzko

In this paper, we give polynomial-time algorithms that can take a graph G with a given combinatorial embedding on an orientable surface S of genus g and produce a planar drawing of G in R^2, with a bounding face defined by a polygonal…

Computational Geometry · Computer Science 2009-08-13 Christian A. Duncan , Michael T. Goodrich , Stephen G. Kobourov

We present an improved algorithm for {\em quasi-properly} learning convex polyhedra in the realizable PAC setting from data with a margin. Our learning algorithm constructs a consistent polyhedron as an intersection of about $t \log t$…

Machine Learning · Computer Science 2021-11-03 Lee-Ad Gottlieb , Eran Kaufman , Aryeh Kontorovich , Gabriel Nivasch

Graph drawing addresses the problem of finding a layout of a graph that satisfies given aesthetic and understandability objectives. The most important objective in graph drawing is minimization of the number of crossings in the drawing, as…

Computational Geometry · Computer Science 2014-01-22 Mohamed A. El-Sayed , S. Abdel-Khalek , Hanan H. Amin

In a planar L-drawing of a directed graph (digraph) each edge e is represented as a polyline composed of a vertical segment starting at the tail of e and a horizontal segment ending at the head of e. Distinct edges may overlap, but not…

Computational Geometry · Computer Science 2020-08-19 Patrizio Angelini , Steven Chaplick , Sabine Cornelsen , Giordano Da Lozzo

We consider upward-planar layered drawings of directed graphs, i.e., crossing-free drawings in which each edge is drawn as a y-monotone curve going upward from its tail to its head, and the y-coordinates of the vertices are integers. The…

Computational Geometry · Computer Science 2026-05-04 Patrizio Angelini , Sabine Cornelsen , Giordano Da Lozzo , Fabrizio Frati , Philipp Kindermann , Ignaz Rutter , Johannes Zink

We prove that every set $\mathcal S$ of $\Delta$ slopes containing the horizontal slope is universal for $1$-bend upward planar drawings of bitonic $st$-graphs with maximum vertex degree $\Delta$, i.e., every such digraph admits a $1$-bend…

Computational Geometry · Computer Science 2018-08-30 Michael A. Bekos , Emilio Di Giacomo , Walter Didimo , Giuseppe Liotta , Fabrizio Montecchiani

Although many machine learning algorithms involve learning subspaces with particular characteristics, optimizing a parameter matrix that is constrained to represent a subspace can be challenging. One solution is to use Riemannian…

Machine Learning · Computer Science 2017-03-10 Stephen Giguere , Francisco Garcia , Sridhar Mahadevan

This paper studies the problem of computing quasi-upward planar drawings of bimodal plane digraphs with minimum curve complexity, i.e., drawings such that the maximum number of bends per edge is minimized. We prove that every bimodal plane…

Computational Geometry · Computer Science 2021-09-14 Carla Binucci , Emilio Di Giacomo , Giuseppe Liotta , Alessandra Tappini

A rectangular drawing of a planar graph $G$ is a planar drawing of $G$ in which vertices are mapped to grid points, edges are mapped to horizontal and vertical straight-line segments, and faces are drawn as rectangles. Sometimes this latter…

Computational Geometry · Computer Science 2024-07-25 Carlos Alegria , Giordano Da Lozzo , Giuseppe Di Battista , Fabrizio Frati , Fabrizio Grosso , Maurizio Patrignani
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