Results 21 to 30 of about 18,159 (263)
Bar 1-Visibility Graphs and their relation to other Nearly Planar Graphs
Journal of Graph Algorithms and Applications, 2014 A graph is called a strong (resp. weak) bar 1-visibility graph if its vertices can be represented as horizontal segments (bars) in the plane so that its edges are all (resp.
William Evans +4 more
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Improved Bounds for Track Numbers of Planar Graphs
Journal of Graph Algorithms and Applications, 2020 A track layout of a graph consists of a vertex coloring and a total order of each color class, such that no two edges cross between any two color classes.
Sergey Pupyrev
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A Planarity Criterion for Graphs [PDF]
SIAM Journal on Discrete Mathematics, 2015 It is proven that a connected graph is planar if and only if all its cocycles with at least four edges are "grounded" in the graph. The notion of grounding of this planarity criterion, which is purely combinatorial, stems from the intuitive idea that with planarity there should be a linear ordering of the edges of a cocycle such that in the two ...
Kosta Dosen, Zoran Petric
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Algorithms and Characterizations for 2-Layer Fan-planarity: From Caterpillar to Stegosaurus
Journal of Graph Algorithms and Applications, 2017 In a fan-planar drawing of a graph there is no edge that crosses two other independent edges. We study 2-layer fan-planar drawings, i.e., fan-planar drawings such that the vertices are restricted to two distinct horizontal layers and edges are straight ...
Carla Binucci +7 more
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Matched Drawings of Planar Graphs
Journal of Graph Algorithms and Applications, 2009 A natural way to draw two planar graphs whose vertex sets are matched is to assign each matched pair a unique y-coordinate. In this paper we introduce the concept of such matched drawings, which is a relaxation of simultaneous geometric embeddings with ...
Emilio Di Giacomo +4 more
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Planar Transitive Graphs [PDF]
The Electronic Journal of Combinatorics, 2018 We prove that the first homology group of every planar locally finite transitive graph $G$ is finitely generated as an $\Aut(G)$-module and we prove a similar result for the fundamental group of locally finite planar Cayley graphs. Corollaries of these results include Droms's theorem that planar groups are finitely presented and Dunwoody's theorem that
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Not all planar graphs are in PURE-4-DIR
Journal of Graph Algorithms and Applications, 2020 We prove that some planar graphs are not intersection graphs of segments if only four slopes are allowed for the segments, and if parallel segments do not intersect. This refutes a conjecture of D. West [D. West, SIAM J. Discrete Math. Newsletter, 1991].
Daniel Gonçalves
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1-Planarity of Graphs with a Rotation System
Journal of Graph Algorithms and Applications, 2015 A graph is 1-planar if it can be drawn in the plane such that each edge is crossed at most once. 1-planarity is known NP-hard, even for graphs of bounded bandwidth, pathwidth, or treewidth, and for near-planar graphs in which an edge is added to a planar
Christopher Auer +3 more
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Simultaneous Drawing of Planar Graphs with Right-Angle Crossings and Few Bends
Journal of Graph Algorithms and Applications, 2016 Given two planar graphs that are defined on the same set of vertices, a RAC simultaneous drawing is a drawing of the two graphs where each graph is drawn planar, no two edges overlap, and edges of one graph can cross edges of the other graph only ...
Michael Bekos +3 more
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Planar Octilinear Drawings with One Bend Per Edge
Journal of Graph Algorithms and Applications, 2015 In octilinear drawings of planar graphs, every edge is drawn as a sequence of horizontal, vertical and diagonal (45°) line segments. In this paper, we study octilinear drawings of low edge complexity, i.e., with few bends per edge.
Michael Bekos +3 more
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