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96
An algorithm for drawing general undirected graphs
 Information Processing Letters
, 1989
"... Graphs (networks) are very common data structures which are handled in computers. Diagrams are widely used to represent the graph structures visually in many information systems. In order to automatically draw the diagrams which are, for example, state graphs, dataflow graphs, Petri nets, and entit ..."
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Cited by 521 (2 self)
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Graphs (networks) are very common data structures which are handled in computers. Diagrams are widely used to represent the graph structures visually in many information systems. In order to automatically draw the diagrams which are, for example, state graphs, dataflow graphs, Petri nets, and entityrelationship diagrams, basic graph drawing algorithms are required.
Multilevel Visualization of Clustered Graphs
, 1997
"... Clustered graphs are graphs with recursive clustering structures over the vertices. This type of structure appears in many systems. Examples include CASE tools, management information systems, VLSI design tools, and reverse engineering systems. Existing layout algorithms represent the clustering str ..."
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Cited by 87 (2 self)
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Clustered graphs are graphs with recursive clustering structures over the vertices. This type of structure appears in many systems. Examples include CASE tools, management information systems, VLSI design tools, and reverse engineering systems. Existing layout algorithms represent the clustering structure as recursively nested regions in the plane. However, as the structure becomes more and more complex, two dimensional plane representations tend to be insufficient. In this paper, firstly, we describe some two dimensional plane drawing algorithms for clustered graphs; then we show how to extend two dimensional plane drawings to three dimensional multilevel drawings. We consider two conventions: straightline convex drawings and orthogonal rectangular drawings; and we show some examples. 1 Introduction Graph drawing algorithms are widely used in graphical user interfaces of software systems. As the amount of information that we want to visualize becomes larger, we need more structure ...
StraightLine Drawing Algorithms for Hierarchical Graphs and Clustered Graphs
 Algorithmica
, 1999
"... Hierarchical graphs and clustered graphs are useful nonclassical graph models for structured relational information. Hierarchical graphs are graphs with layering structures; clustered graphs are graphs with recursive clustering structures. Both have applications in CASE tools, software visualizatio ..."
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Cited by 60 (12 self)
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Hierarchical graphs and clustered graphs are useful nonclassical graph models for structured relational information. Hierarchical graphs are graphs with layering structures; clustered graphs are graphs with recursive clustering structures. Both have applications in CASE tools, software visualization, and VLSI design. Drawing algorithms for hierarchical graphs have been well investigated. However, the problem of straightline representation has not been solved completely. In this paper, we answer the question: does every planar hierarchical graph admit a planar straightline hierarchical drawing? We present an algorithm that constructs such drawings in linear time. Also, we answer a basic question for clustered graphs, that is, does every planar clustered graph admit a planar straightline drawing with clusters drawn as convex polygons? We provide a method for such drawings based on our algorithm for hierarchical graphs.
Maximum Planar Subgraphs and Nice Embeddings: Practical Layout Tools
 ALGORITHMICA
, 1996
"... ..."
A Better Approximation Algorithm for Finding Planar Subgraphs
 J. ALGORITHMS
, 1996
"... The MAXIMUM PLANAR SUBGRAPH problemgiven a graph G, find a largest planar subgraph of Ghas applications in circuit layout, facility layout, and graph drawing. No previous polynomialtime approximation algorithm for this NPComplete problem was known to achieve a performance ratio larger than ..."
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Cited by 29 (4 self)
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The MAXIMUM PLANAR SUBGRAPH problemgiven a graph G, find a largest planar subgraph of Ghas applications in circuit layout, facility layout, and graph drawing. No previous polynomialtime approximation algorithm for this NPComplete problem was known to achieve a performance ratio larger than 1=3, which is achieved simply by producing a spanning tree of G. We present the first approximation algorithm for MAXIMUM PLANAR SUBGRAPH with higher performance ratio (4=9 instead of 1=3). We also apply our algorithm to find large outerplanar subgraphs. Last, we show that both MAXIMUM PLANAR SUBGRAPH and its complement, the problem of removing as few edges as possible to leave a planar subgraph, are Max SNPHard.
Guidelines of Business Process Modeling
 IN: BUSINESS PROCESS MANAGEMENT: MODELS, TECHNIQUES AND EMPIRICAL STUDIES. EDS
, 2000
"... Process modeling becomes more and more an important task not only for the purpose of software engineering, but also for many other purposes besides the development of software. Therefore it is necessary to evaluate the quality of process models from different viewpoints. This is even more import ..."
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Cited by 27 (5 self)
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Process modeling becomes more and more an important task not only for the purpose of software engineering, but also for many other purposes besides the development of software. Therefore it is necessary to evaluate the quality of process models from different viewpoints. This is even more important as the increasing number of different end users, different purposes and the availability of different modeling techniques and modeling tools leads to a higher complexity of information models. In this paper the Guidelines of Modeling (GoM), a framework to structure factors for the evaluation of process models, is presented. Exemplary, Guidelines of Modeling for workflow management and simulation are presented. Moreover, six general techniques for adjusting models to the perspectives of different types of user and purposes will be explained.
GraphEd: A Graphical Platform for the Implementation of Graph Algorithms (Extended Abstract and Demo)
 Graph Drawing (Proc. GD '94), volume 894 of Lecture Notes in Computer Science
"... and Demo) Michael Himsolt Universitat Passau, 94032 Passau, GERMANY himsolt@fmi.unipassau.de Abstract. GraphEd is an extensible graph editor. Its powerful object oriented user interface supports all operations that are necessary for the convenient construction and manipulation of graphs. Graph gr ..."
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Cited by 25 (4 self)
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and Demo) Michael Himsolt Universitat Passau, 94032 Passau, GERMANY himsolt@fmi.unipassau.de Abstract. GraphEd is an extensible graph editor. Its powerful object oriented user interface supports all operations that are necessary for the convenient construction and manipulation of graphs. Graph grammars can be used as a macro system to create structured graphs. GraphEd's modular structure and the application interface support the easy integration of algorithm modules which are written in C, or can run external programs. The user may construct graphs interactively, select algorithms from a menu, and view the results of an algorithm directly on screen. Several graph layout algorithms assist the user to tidy graph drawings, and help the programmer to visualize results or debug complex algorithms. Actual applications range from standard graph algorithms over graph drawing algorithms, algorithm animation and combinatorial algorithms to front ends for circuit design systems. 1 Introduction...
Parallel transitive closure and point location in planar structures
 SIAM J. COMPUT
, 1991
"... Parallel algorithms for several graph and geometric problems are presented, including transitive closure and topological sorting in planar stgraphs, preprocessing planar subdivisions for point location queries, and construction of visibility representations and drawings of planar graphs. Most of th ..."
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Cited by 24 (12 self)
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Parallel algorithms for several graph and geometric problems are presented, including transitive closure and topological sorting in planar stgraphs, preprocessing planar subdivisions for point location queries, and construction of visibility representations and drawings of planar graphs. Most of these algorithms achieve optimal O(log n) running time using n = log n processors in the EREW PRAM model, n being the number of vertices.
QBD * : A Fully Visual Query System
"... The need of a friendly manmachine interaction is becoming crucial for a large variety of applications, in particular, those requiring frequent extraction of information from the database. Experience suggests that traditional query languages are not friendly enough for the casual user: she/he is req ..."
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Cited by 23 (5 self)
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The need of a friendly manmachine interaction is becoming crucial for a large variety of applications, in particular, those requiring frequent extraction of information from the database. Experience suggests that traditional query languages are not friendly enough for the casual user: she/he is requested to formulate queries in a textual language, without any iconic or spatial clues to help the querying process. A new generation of languages (visual languages) has been recently investigated, that attempts to make extensive use of the person's instincts and senses. In this paper we propose a fully visual system, called Query by Diagram* (QBD*), which is based on a conceptual data model, a query language defined on this model and a graphical user interface. The main characteristics of the interface are the ease of use, and the availability of a rich set of primitives for both schema selection and query formulation. Unlike many present proposals of graphical query systems, graphical oper...