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Graph Drawings with Few Slopes

Vida Dujmovic'·Matthew Suderman·David R. Wood
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Abstract

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 $Δ\geq5$ and all large $n$, there is a $Δ$-regular $n$-vertex graph with slope-number at least $n^{1-\frac{8+ε}{Δ+4}}$. This is the best known lower bound on the slope-number of a graph with bounded degree. We prove upper and lower bounds on the slope-number of complete bipartite graphs. We prove a general upper bound on the slope-number of an arbitrary graph in terms of its bandwidth. It follows that the slope-number of interval graphs, cocomparability graphs, and AT-free graphs is at most a function of the maximum degree. We prove that graphs of bounded degree and bounded treewidth have slope-number at most $O(\log n)$. Finally we prove that every graph has a drawing with one bend per edge, in which the number of slopes is at most one more than the maximum degree. In a companion paper (http://arxiv.org/abs/math/0606450), planar drawings of graphs with few slopes are also considered.

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BibTeXRIS

Vida Dujmovic', Matthew Suderman, David R. Wood. 2006-06-19. Graph Drawings with Few Slopes. https://doi.org/10.1016/j.comgeo.2006.08.002

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