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arXiv · 1708.09778

Drawing bobbin lace graphs, or, Fundamental cycles for a subclass of periodic graphs

Therese Biedl·Veronika Irvine
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Abstract

In this paper, we study a class of graph drawings that arise from bobbin lace patterns. The drawings are periodic and require a combinatorial embedding with specific properties which we outline and demonstrate can be verified in linear time. In addition, a lace graph drawing has a topological requirement: it contains a set of non-contractible directed cycles which must be homotopic to $(1,0)$, that is, when drawn on a torus, each cycle wraps once around the minor meridian axis and zero times around the major longitude axis. We provide an algorithm for finding the two fundamental cycles of a canonical rectangular schema in a supergraph that enforces this topological constraint. The polygonal schema is then used to produce a straight-line drawing of the lace graph inside a rectangular frame. We argue that such a polygonal schema always exists for combinatorial embeddings satisfying the conditions of bobbin lace patterns, and that we can therefore create a pattern, given a graph with a fixed combinatorial embedding of genus one.

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Therese Biedl, Veronika Irvine. 2017-09-07. Drawing bobbin lace graphs, or, Fundamental cycles for a subclass of periodic graphs. https://arxiv.org/abs/1708.09778

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