Results 1 to 10 of about 2,825 (206)
GA for straight-line grid drawings of maximal planar graphs
A straight-line grid drawing of a planar graph G of n vertices is a drawing of G on an integer grid such that each vertex is drawn as a grid point and each edge is drawn as a straight-line segment without edge crossings.
Mohamed A. El-Sayed
doaj +4 more sources
Straight-line drawings of 1-planar graphs
A graph is 1-planar if it can be drawn in the plane so that each edge is crossed at most once. However, there are 1-planar graphs which do not admit a straight-line 1-planar drawing. We show that every 1-planar graph has a straight-line drawing with a two-coloring of the edges, so that edges of the same color do not cross.
Franz J. Brandenburg
openalex +3 more sources
Straight-line Drawability of a Planar Graph Plus an Edge [PDF]
We investigate straight-line drawings of topological graphs that consist of a planar graph plus one edge, also called almost-planar graphs. We present a characterization of such graphs that admit a straight-line drawing. The characterization enables a linear-time testing algorithm to determine whether an almost-planar graph admits a straight-line ...
Peter Eades+4 more
+7 more sources
Edge-Disjoint Homotopic Paths in Straight-Line Planar Graphs [PDF]
Let G be a planar graph, embedded without crossings in the euclidean plane $\mathbb{R}^2 $, and let $I_1 , \cdots ,I_p $ be some of its faces (including the unbounded face), considered as open sets. Suppose there exist (straight) line segments $L_1 , \cdots ,L_t $ in $\mathbb{R}^2 $ so that $G \cup I_1 \cup \cdots \cup I_p = L_1 \cup \cdots \cup L_t ...
Alexander Schrijver
openalex +3 more sources
A Note on Minimum-Area Straight-Line Drawings of Planar Graphs [PDF]
Despite a long research effort, finding the minimum area for straight-line grid drawings of planar graphs is still an elusive goal. A long-standing lower bound on the area requirement for straight-line drawings of plane graphs was established in 1984 by Dolev, Leighton, and Trickey, who exhibited a family of graphs, known as nested triangles graphs ...
Fabrizio Frati, Maurizio Patrignani
openalex +6 more sources
Minimum Weight Connectivity Augmentation for Planar Straight-Line Graphs [PDF]
15 pages, 7 figures, to appear in the Proceedings of WALCOM ...
Hugo A. Akitaya+5 more
openalex +6 more sources
Encompassing colored planar straight line graphs
AbstractConsider a planar straight line graph (PSLG), G, with k connected components, k⩾2. We show that if no component is a singleton, we can always find a vertex in one component that sees an entire edge in another component. This implies that when the vertices of G are colored, so that adjacent vertices have different colors, then (1) we can augment
Ferrán Hurtado+3 more
openalex +3 more sources
Refining a triangulation of a planar straight-line graph to eliminate large angles [PDF]
We show that any planar straight line graph (PSLG) with v vertices can be triangulated with no angle larger than 7/spl pi//8 by adding O(v/sup 2/log v) Steiner points in O(v/sup 2/log/sup 2/ v) time. We first triangulate the PSLG with an arbitrary constrained triangulation and then refine that triangulation by adding additional vertices and edges.
Scott A. Mitchell
openalex +4 more sources
Connectivity augmentation in planar straight line graphs
AbstractIt is shown that every connected planar straight line graph with n≥3 vertices has an embedding preserving augmentation to a 2-edge connected planar straight line graph with at most ⌊(2n−2)/3⌋ new edges. It is also shown that every planar straight line tree with n≥3 vertices has an embedding preserving augmentation to a 2-edge connected planar ...
Csaba D. Tóth
openalex +4 more sources
A Linear Time Algorithm for Constructing Maximally Symmetric Straight Line Drawings of Triconnected Planar Graphs [PDF]
Symmetry is one of the most important aesthetic criteria in graph drawing because it reveals structure in the graph. To draw graphs symmetrically, we employ two steps.
Seok-Hee Hong+2 more
+8 more sources