Placing Arrows in Directed Graph Drawings

TL;DR

This paper addresses the challenge of placing arrowheads in directed graph drawings to ensure clarity without overlaps, presenting complexity results, algorithms, and practical evaluations.

Contribution

It introduces the problem of arrow placement in directed graphs, proves its computational hardness, and offers both exact and heuristic solutions along with a practical study.

Findings

Arrow placement problem is NP-hard.

Proposed algorithms improve clarity in graph drawings.

Practical methods are effective for real-world graphs.

Abstract

We consider the problem of placing arrow heads in directed graph drawings without them overlapping other drawn objects. This gives drawings where edge directions can be deduced unambiguously. We show hardness of the problem, present exact and heuristic algorithms, and report on a practical study.