Results 1  10
of
18
Automatic graph drawing and readability of diagrams
 IEEE Transactions on Systems, Man and Cybernetics
, 1988
"... AhtractDiagrams are widely used in several areas of computer wience, and their effectiveness is thoroughly recognized. One of the main qualities requested for them is readability; this is especially, but not exclusively, true in the area of information systems, where diagrams are used to model data ..."
Abstract

Cited by 92 (8 self)
 Add to MetaCart
AhtractDiagrams are widely used in several areas of computer wience, and their effectiveness is thoroughly recognized. One of the main qualities requested for them is readability; this is especially, but not exclusively, true in the area of information systems, where diagrams are used to model data and functions of the application. Up to now, diagrams have been produced manually or with the aid of a graphic editor; in both caws placement of symbols and routing of connections are under responsibility of the designer. The goal of the work is to investigate how readability of diagrams can be achieved by means of automatic tools. Existing results in the literature are compared, and a comprehensive algorithmic approach to the problem is proposed. The algorithm presented draws graphs on a grid and is suitable for both undirected graphs and mixed graphs that contain as subgraphs hierarchic structures. Finally, several applications of a graphic tool that embodies the aforementioned facility are shown. I.
ThreeDimensional Orthogonal Graph Drawing
, 2000
"... vi Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix List of Tables . . . . . . . . . . . . ..."
Abstract

Cited by 27 (10 self)
 Add to MetaCart
vi Declaration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii List of Algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiv I Orthogonal Graph Drawing 1 1
Algorithms for Drawing Clustered Graphs
, 1997
"... In the mid 1980s, graphics workstations became the main platforms for software and information engineers. Since then, visualization of relational information has become an essential element of software systems. Graphs are commonly used to model relational information. They are depicted on a graphics ..."
Abstract

Cited by 25 (2 self)
 Add to MetaCart
In the mid 1980s, graphics workstations became the main platforms for software and information engineers. Since then, visualization of relational information has become an essential element of software systems. Graphs are commonly used to model relational information. They are depicted on a graphics workstation as graph drawings. The usefulness of the relational model depends on whether the graph drawings effectively convey the relational information to the users. This thesis is concerned with finding good drawings of graphs. As the amount of information that we want to visualize becomes larger and the relations become more complex, the classical graph model tends to be inadequate. Many extended models use a node hierarchy to help cope with the complexity. This thesis introduces a new graph model called the clustered graph. The central theme of the thesis is an investigation of efficient algorithms to produce good drawings for clustered graphs. Although the criteria for judging the qua...
MultiDimensional Orthogonal Graph Drawing with Small Boxes
 Proc. 7th International Symp. on Graph Drawing (GD '99
, 1999
"... In this paper we investigate the general position model for the drawing of arbitrary degree graphs in the Ddimensional (D >= 2) orthogonal grid. In this model no two vertices lie in the same grid hyperplane. ..."
Abstract

Cited by 13 (5 self)
 Add to MetaCart
In this paper we investigate the general position model for the drawing of arbitrary degree graphs in the Ddimensional (D >= 2) orthogonal grid. In this model no two vertices lie in the same grid hyperplane.
The Rectangle of Influence Drawability Problem
 Computational Geometry: Theory and Applications
, 1997
"... Motivated by rectangular visibility and graph drawing applications, we study the problem of characterizing classes of graphs that admit rectangle of influence drawings. We consider several classes of graphs and show, for each class, that testing whether a graph G has a rectangle of influence draw ..."
Abstract

Cited by 10 (2 self)
 Add to MetaCart
Motivated by rectangular visibility and graph drawing applications, we study the problem of characterizing classes of graphs that admit rectangle of influence drawings. We consider several classes of graphs and show, for each class, that testing whether a graph G has a rectangle of influence drawing can be done in O(n) time, where n is the number of vertices of G. If the test for G is affirmative, we show how to construct a rectangle of influence drawing of G. All the drawing algorithms can be implemented so that they (1) produce drawings with all vertices placed at intersection points of an integer grid of size O(n 2 ), (2) perform arithmetic operations on integers only, and (3) run in O(n) time, where n is the number of vertices of the input graph. 1 Introduction A proximity drawing of a graph is a straightline drawing (vertices are represented by points and edges by straightline segments) where the points representing adjacent vertices are deemed to be close according t...
Drawing High Degree Graphs with Low Bend Numbers
 PROC. 4TH SYMPOSIUM ON GRAPH DRAWING (GD'95), LNCS 1027
, 1995
"... We consider the problem of drawing plane graphs with an arbitrarily high vertex degree orthogonally into the plane such that the number of bends on the edges should be minimized. It has been known how to achieve the bend minimum without any respect to the size of the vertices. Naturally, the vertice ..."
Abstract

Cited by 9 (1 self)
 Add to MetaCart
We consider the problem of drawing plane graphs with an arbitrarily high vertex degree orthogonally into the plane such that the number of bends on the edges should be minimized. It has been known how to achieve the bend minimum without any respect to the size of the vertices. Naturally, the vertices should be represented by uniformly small squares. In addition we might require that each face should be represented by a nonempty region. This would allow a labeling of the faces. We present an efficient algorithm which provably achieves the bend minimum following these constraints. Omitting the latter requirement we conjecture that the problem becomes NPhard. For that case, we give advices for good approximations. We demonstrate the effectiveness of our approaches giving some interesting examples.
Experiments on exact crossing minimization using column generation
 ACM Journal of Experimental Algorithmics
"... Abstract. The crossing number of a graph G is the smallest number of edge crossings in any drawing of G into the plane. Recently, the first branchandcut approach for solving the crossing number problem has been presented in [3]. Its major drawback was the huge number of variables out of which only ..."
Abstract

Cited by 6 (6 self)
 Add to MetaCart
Abstract. The crossing number of a graph G is the smallest number of edge crossings in any drawing of G into the plane. Recently, the first branchandcut approach for solving the crossing number problem has been presented in [3]. Its major drawback was the huge number of variables out of which only very few were actually used in the optimal solution. This restricted the algorithm to rather small graphs with low crossing number. In this paper we discuss two column generation schemes; the first is based on traditional algebraic pricing, and the second uses combinatorial arguments to decide whether and which variables need to be added. The main focus of this paper is the experimental comparison between the original approach, and these two schemes. We also compare these new results to the solutions of the best known crossing number heuristic. 1
Approximating the Crossing Number of Graphs Embeddable In Any Orientable Surface
"... The crossing number of a graph is the least number of pairwise edge crossings in a drawing of the graph in the plane. We provide an O(n log n) time constant factor approximation algorithm for the crossing number of a graph of bounded maximum degree which is “densely enough” embeddable in an arbitrar ..."
Abstract

Cited by 5 (3 self)
 Add to MetaCart
The crossing number of a graph is the least number of pairwise edge crossings in a drawing of the graph in the plane. We provide an O(n log n) time constant factor approximation algorithm for the crossing number of a graph of bounded maximum degree which is “densely enough” embeddable in an arbitrary fixed orientable surface. Our approach combines some known tools with a powerful new lower bound on the crossing number of an embedded graph. This result extends previous results that gave such approximations in particular cases of projective, toroidal or apex graphs; it is a qualitative improvement over previously published algorithms that constructed lowcrossingnumber drawings of embeddable graphs without giving any approximation guarantees. No constant factor approximation algorithms for the crossing number problem over comparably rich classes of graphs are known to date.
Orthogonal Drawings Based On The Stratification Of Planar Graphs
, 2000
"... Several algorithms have been proposed to draw planar graphs using 2visibility and Kandinsky Models. Here, we propose three new algorithms implementing these models in linear time using small grid sizes and few bends. These algorithms are all based on the construction of a particular layered spannin ..."
Abstract

Cited by 4 (2 self)
 Add to MetaCart
Several algorithms have been proposed to draw planar graphs using 2visibility and Kandinsky Models. Here, we propose three new algorithms implementing these models in linear time using small grid sizes and few bends. These algorithms are all based on the construction of a particular layered spanning tree called Stratification. A linear time algorithm that computes a stratification is also presented.
Minimum depth graph embedding
 Proc. ESA’00, volume 1879 of LNCS
, 2000
"... Abstract. The depth of a planar embedding is a measure of the topological nesting of the biconnected components of the graph. Minimizing the depth of planar embeddings has important practical applications to graph drawing. We give a linear time algorithm for computing a minimum depth embedding of a ..."
Abstract

Cited by 3 (0 self)
 Add to MetaCart
Abstract. The depth of a planar embedding is a measure of the topological nesting of the biconnected components of the graph. Minimizing the depth of planar embeddings has important practical applications to graph drawing. We give a linear time algorithm for computing a minimum depth embedding of a planar graphs whose biconnected components have a prescribed embedding. 1