We study the problem of producing hierarchical drawings of layered graphs when some pairs of edges are not allowed to cross. We show that deciding on the existence of a drawing satisfying at least k constraints from a given set of non-crossing constraints is NP-complete even if the graph is 2-layered and even when the permutation of the vertices on one side of the bipartition is fixed. We also propose simple constant-ratio approximation algorithms for the optimization version of the problem and we discuss how to extend the well-known hierarchical approach for creating layered drawings of directed graphs with the capability of minimizing the number of edge crossings while maximizing the number of satisfied non-crossing constraints.
|Titolo:||Layered drawings of graphs with crossing constraints|
|Data di pubblicazione:||2001|
|Appare nelle tipologie:||04.1 - Contributo in Atti di convegno (Paper in Proceedings)|