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Related papers: Outerplanar graph drawings with few slopes

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We consider drawings of graphs in the plane in which edges are represented by polygonal paths with at most one bend and the number of different slopes used by all segments of these paths is small. We prove that…

Computational Geometry · Computer Science 2015-09-29 Kolja Knauer , Bartosz Walczak

We describe a set of $\Delta -1$ slopes that are universal for 1-bend planar drawings of planar graphs of maximum degree $\Delta \geq 4$; this establishes a new upper bound of $\Delta-1$ on the 1-bend planar slope number. By universal we…

Computational Geometry · Computer Science 2017-03-14 Patrizio Angelini , Michael A. Bekos , Giuseppe Liotta , Fabrizio Montecchiani

We study straight-line drawings of planar graphs with few segments and few slopes. Optimal results are obtained for all trees. Tight bounds are obtained for outerplanar graphs, 2-trees, and planar 3-trees. We prove that every 3-connected…

Combinatorics · Mathematics 2008-09-09 Vida Dujmovic' , David Eppstein , Matthew Suderman , David R. Wood

The "slope-number" of a graph $G$ is the minimum number of distinct edge slopes in a straight-line drawing of $G$ in the plane. We prove that for $\Delta\geq5$ and all large $n$, there is a $\Delta$-regular $n$-vertex graph with…

Combinatorics · Mathematics 2008-09-09 Vida Dujmovic' , Matthew Suderman , David R. Wood

We settle a problem of Dujmovi\'c, Eppstein, Suderman, and Wood by showing that there exists a function $f$ with the property that every planar graph $G$ with maximum degree $d$ admits a drawing with noncrossing straight-line edges, using…

Combinatorics · Mathematics 2010-11-13 Balázs Keszegh , János Pach , Dömötör Pálvölgyi

It is known that every planar graph has a planar embedding where edges are represented by non-crossing straight-line segments. We study the planar slope number, i.e., the minimum number of distinct edge-slopes in such a drawing of a planar…

We show that any outerplanar graph admits a planar straightline drawing such that the length ratio of the longest to the shortest edges is strictly less than 2. This result is tight in the sense that for any $\epsilon > 0$ there are…

Computational Geometry · Computer Science 2017-09-04 Sylvain Lazard , William Lenhart , Giuseppe Liotta

It is proved that every series-parallel digraph whose maximum vertex-degree is $\Delta$ admits an upward planar drawing with at most one bend per edge such that each edge segment has one of $\Delta$ distinct slopes. This is shown to be…

Computational Geometry · Computer Science 2016-08-31 Emilio Di Giacomo , Giuseppe Liotta , Fabrizio Montecchiani

An outer-1-planar graph is a graph admitting a drawing in the plane so that all vertices appear in the outer region of the drawing and every edge crosses at most one other edge. This paper establishes the local structure of outer-1-planar…

Combinatorics · Mathematics 2023-06-22 Yan Li , Xin Zhang

A graph is outer-1-planar if it can be drawn in the plane so that all vertices are on the outer face and each edge is crossed at most once. It is known that the list edge chromatic number $\chi'_l(G)$ of any outer-1-planar graph $G$ with…

Combinatorics · Mathematics 2019-02-13 Xin Zhang

In octilinear drawings of planar graphs, every edge is drawn as an alternating sequence of horizontal, vertical and diagonal ($45^\circ$) line-segments. In this paper, we study octilinear drawings of low edge complexity, i.e., with few…

Data Structures and Algorithms · Computer Science 2014-08-27 Michael A. Bekos , Martin Gronemann , Michael Kaufmann , Robert Krug

A graph is pseudo-outerplanar if each of its blocks has an embedding in the plane so that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. It is proved that…

Combinatorics · Mathematics 2013-04-24 Xin Zhang

An octilinear drawing of a planar graph is one in which each edge is drawn as a sequence of horizontal, vertical and diagonal at 45 degrees line-segments. For such drawings to be readable, special care is needed in order to keep the number…

Computational Geometry · Computer Science 2015-12-16 Michael A. Bekos , Michael Kaufmann , Robert Krug

In this paper, we show that all simple outerplanar graphs $G$ with minimum degree at least $2$ and positive Lin-Lu-Yau Ricci curvature on every edge have maximum degree at most $9$. Furthermore, if $G$ is maximally outerplanar, then $G$ has…

Combinatorics · Mathematics 2025-10-01 George Brooks , Fadekemi Osaye , Anna Schenfisch , Zhiyu Wang , Jing Yu

We provide two constructions for $t$ edge-disjoint maximal outerplanar graphs on every number of $n \geq 4t$ vertices. The bound on the minimum number of vertices is tight. These constructions yield the existence of optimal…

Combinatorics · Mathematics 2026-01-12 Yuto Okada , Yota Otachi , Lena Volk

A graph is 1-planar if it can be drawn in the plane such that each edge is crossed at most once. A graph, together with a 1-planar drawing is called 1-plane. Brandenburg et al. showed that there are maximal 1-planar graphs with only…

Combinatorics · Mathematics 2015-09-21 János Barát , Géza Tóth

The $\textit{planar slope number}$ $psn(G)$ of a planar graph $G$ is the minimum number of edge slopes in a planar straight-line drawing of $G$. It is known that $psn(G) \in O(c^\Delta)$ for every planar graph $G$ of maximum degree…

Computational Geometry · Computer Science 2023-11-29 Steven Chaplick , Giordano Da Lozzo , Emilio Di Giacomo , Giuseppe Liotta , Fabrizio Montecchiani

The slope number of a graph $G$ is the smallest number of slopes needed for the segments representing the edges in any straight-line drawing of $G$. It serves as a measure of the visual complexity of a graph drawing. Several bounds on the…

Computational Geometry · Computer Science 2022-10-13 Jonathan Klawitter , Johannes Zink

A graph is called pseudo-outerplanar if each block has an embedding on the plane in such a way that the vertices lie on a fixed circle and the edges lie inside the disk of this circle with each of them crossing at most one another. In this…

Combinatorics · Mathematics 2011-10-20 Xin Zhang , Guizhen Liu , Jian-Liang Wu

A graph is 1-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge. In this note we give examples of class two 1-planar graphs with maximum degree six or seven.

Combinatorics · Mathematics 2011-04-26 Xin Zhang
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