Train Tracks and Confluent Drawings

  • Peter Hui
  • Marcus Schaefer
  • Daniel Štefankovič
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3383)


Confluent graphs capture the connection properties of train tracks, offering a very natural generalization of planar graphs, and – as the example of railroad maps shows – are an important tool in graph visualization. In this paper we continue the study of confluent graphs, introducing strongly confluent graphs and tree-confluent graphs. We show that strongly confluent graphs can be recognized in NP (the complexity of recognizing confluent graphs remains open). We also give a natural elimination ordering characterization of tree-confluent graphs which shows that they form a subclass of the chordal bipartite graphs, and can be recognized in polynomial time.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Peter Hui
    • 1
  • Marcus Schaefer
    • 1
  • Daniel Štefankovič
    • 2
  1. 1.Department of Computer ScienceDePaul UniversityChicago
  2. 2.Department of Computer ScienceUniversity of ChicagoChicago

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