Building Blocks of Upward Planar Digraphs

The upward planarity testing problem consists of testing if a digraph admits a drawing Γ such that all edges in Γ are monotonically increasing in the vertical direction and no edges in Γ cross. In this paper we reduce the problem of testing a digraph for upward planarity to the problem of testing if its blocks admit upward planar drawings with certain properties. We also show how to test if a block of a digraph admits an upward planar drawing with the aforementioned properties. Article Type Communicated by Submitted Revised Regular Paper G. Di Battista May 2005 August 2006 

• Type: Conference
• Year: 2004
• Where: GD
• Authors: Patrick Healy, Karol Lynch
• Keywords: GD 2004, Upward Planar Drawing, Upward Planarity, Upward Planarity Testing