منابع مشابه
Orthogonal-Ordering Constraints are Tough
We show that rectilinear graph drawing, the core problem of bendminimum orthogonal graph drawing, and uniform edge-length drawing, the core problem of force-directed placement, are NP-hard even for embedded paths if subjected to orthogonal-ordering constraints. Submitted: June 2010 Reviewed: April 2011 Revised: September 2012 Accepted: November 2012 Final: December 2012 Published: January 2013 ...
متن کاملStress Majorization with Orthogonal Ordering Constraints
The adoption of the stress-majorization method frommulti-dimensional scaling into graph layout has provided an improved mathematical basis and better convergence properties for so-called “force-directed placement” techniques. In this paper we give an algorithm for augmenting such stress-majorization techniques with orthogonal ordering constraints and we demonstrate several graphdrawing applicat...
متن کاملSolving Simplification Ordering Constraints
This paper considers the decision problem for the existential fragment of the theory of simplification orderings. A simple, polynomial-time procedure for deciding satisfiability of such constraints is given, and it is also shown that the corresponding problem for the theory of total simplification orderings is NP-complete. This latter result can be interpreted as showing that the problem of dec...
متن کاملSymmetry Breaking Ordering Constraints
In a constraint satisfaction problem (CSP), symmetry involves the variables, values in the domains, or both, and maps each search state into an equivalent one. When searching for solutions, symmetrically equivalent (partial) assignments can dramatically increase the search space. Hence, elimination of symmetry is essential to avoid exploring equivalent branches in a search tree. An important cl...
متن کاملSolving Symbolic Ordering Constraints
Received Revised ABSTRACT We show how to solve boolean combinations of inequations s > t in the Herbrand Universe, assuming that is interpreted as a lexicographic path ordering extending a total precedence. In other words, we prove that the existential fragment of the theory of a lexicographic path ordering which extends a total precedence is decidable.
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ژورنال
عنوان ژورنال: Journal of Graph Algorithms and Applications
سال: 2013
ISSN: 1526-1719
DOI: 10.7155/jgaa.00281