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Graphviz
Graphviz (short for ''Graph Visualization Software'') is a package of open-source software, open-source tools initiated by AT&T Labs, AT&T Labs Research for Graph drawing, drawing graph (discrete mathematics), graphs (as in Vertex (graph theory), nodes and Edge (graph theory), edges, not as in bar charts) specified in DOT (graph description language), DOT language scripts having the file name extension "gv". It also provides libraries for software applications to use the tools. Graphviz is free software licensed under the Eclipse Public License. Tools ; dot : a Command-line interface, command-line tool to produce layered graph drawing, layered graph drawings in a variety of output formats, such as (PostScript, PDF, Scalable Vector Graphics, SVG, annotated text and so on). ; neato : useful for undirected graphs up to about 1000 nodes. "Spring system, Spring model" layout minimizes global energy. ; fdp : force-directed graph drawing similar to "spring model", but minimizes forc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DOT (graph Description Language)
DOT is a Graph (discrete mathematics), graph description language, developed as a part of the Graphviz project. DOT graphs are typically stored as Computer file, files with the .gv or .dot filename extension — .gv is preferred, to avoid confusion with the .dot extension used by versions of Microsoft Word before 2007. dot is also the name of the main program to process DOT files in the Graphviz package. Various programs can process DOT files. Some, such as ''dot'', ''neato'', ''twopi'', ''circo'', ''fdp'', and ''sfdp'', can read a DOT file and render it in graphical form. Others, such as ''gvpr'', ''gc'', ''acyclic'', ''ccomps'', ''sccmap'', and ''tred'', read DOT files and perform calculations on the represented graph. Finally, others, such as ''lefty'', ''dotty'', and ''grappa'', provide an interactive interface. The GVedit tool combines a text editor and a non-interactive viewer. Most programs are part of the Graphviz package or use it internally. DOT is historically an acron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Layered Graph Drawing
Layered graph drawing or hierarchical graph drawing is a type of graph drawing in which the vertices of a directed graph are drawn in horizontal rows or layers with the edges generally directed downwards.... It is also known as Sugiyama-style graph drawing after Kozo Sugiyama, who first developed this drawing style. The ideal form for a layered drawing would be an upward planar drawing, in which all edges are oriented in a consistent direction and no pairs of edges cross. However, graphs often contain cycles, minimizing the number of inconsistently oriented edges is NP-hard, and minimizing the number of crossings is also NP-hard; so, layered graph drawing systems typically apply a sequence of heuristics that reduce these types of flaws in the drawing without guaranteeing to find a drawing with the minimum number of flaws. Layout algorithm The construction of a layered graph drawing proceeds in a sequence of steps: *If the input graph is not already a directed acyclic graph, a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Drawing
Graph drawing is an area of mathematics and computer science combining methods from geometric graph theory and information visualization to derive two-dimensional depictions of graph (discrete mathematics), graphs arising from applications such as social network analysis, cartography, linguistics, and bioinformatics. A drawing of a graph or network diagram is a pictorial representation of the vertex (graph theory), vertices and edge (graph theory), edges of a graph. This drawing should not be confused with the graph itself: very different layouts can correspond to the same graph., p. 6. In the abstract, all that matters is which pairs of vertices are connected by edges. In the concrete, however, the arrangement of these vertices and edges within a drawing affects its understandability, usability, fabrication cost, and aesthetics. The problem gets worse if the graph changes over time by adding and deleting edges (dynamic graph drawing) and the goal is to preserve the user's men ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Modelling Language
Graph Modeling Language (GML) is a hierarchical ASCII-based file format for describing graphs. It has been also named ''Graph Meta Language''. Example A simple graph in GML format: graph comment "This is a sample graph" directed 1 id 42 label "Hello, I am a graph" node [ id 1 label "node 1" thisIsASampleAttribute 42 node [ id 2 label "node 2" thisIsASampleAttribute 43 ] node [ id 3 label "node 3" thisIsASampleAttribute 44 ] edge [ source 1 target 2 label "Edge from node 1 to node 2" ] edge [ source 2 target 3 label "Edge from node 2 to node 3" ] edge source 3 target 1 label "Edge from node 3 to node 1" ] Applications supporting GML * Cytoscape, an open source bioinformatics software platform for visualizing molecular interaction networks, loads and save previously-constructed interaction networks in GML. * igraph, an open source network analysis library with interfaces to multiple programming languages. * Gephi, an open sou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipse Public License
The Eclipse Public License (EPL) is a free and open source software license most notably used for the Eclipse IDE and other projects by the Eclipse Foundation. It replaces the Common Public License (CPL) and removes certain terms relating to litigations related to patents.In section 7, this sentence is in CPL 1.0, but not EPL 1.0: "If Recipient institutes patent litigation against a Contributor with respect to a patent applicable to software (including a cross-claim or counterclaim in a lawsuit), then any patent licenses granted by that Contributor to such Recipient under this Agreement shall terminate as of the date such litigation is filed." The Eclipse Public License is designed to be a business-friendly free software license, and features weaker copyleft provisions than licenses such as the GNU General Public License (GPL). The receiver of EPL-licensed programs can use, modify, copy and distribute the work and modified versions, in some cases being obligated to release ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Force-directed Graph Drawing
Force-directed graph drawing algorithms are a class of algorithms for drawing graphs in an aesthetically-pleasing way. Their purpose is to position the nodes of a graph in two-dimensional or three-dimensional space so that all the edges are of more or less equal length and there are as few crossing edges as possible, by assigning forces among the set of edges and the set of nodes, based on their relative positions, and then using these forces either to simulate the motion of the edges and nodes or to minimize their energy. While graph drawing can be a difficult problem, force-directed algorithms, being physical simulations, usually require no special knowledge about graph theory such as planarity. Forces Force-directed graph drawing algorithms assign forces among the set of edges and the set of nodes of a graph drawing. Typically, spring-like attractive forces based on Hooke's law are used to attract pairs of endpoints of the graph's edges towards each other, while simultaneo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PostScript
PostScript (PS) is a page description language and dynamically typed, stack-based programming language. It is most commonly used in the electronic publishing and desktop publishing realm, but as a Turing complete programming language, it can be used for many other purposes as well. PostScript was created at Adobe Systems by John Warnock, Charles Geschke, Doug Brotz, Ed Taft and Bill Paxton from 1982 to 1984. The most recent version, PostScript 3, was released in 1997. History The concepts of the PostScript language were seeded in 1976 by John Gaffney at Evans & Sutherland, a computer graphics company. At that time, Gaffney and John Warnock were developing an interpreter for a large three-dimensional graphics database of New York Harbor. Concurrently, researchers at Xerox PARC had developed the first laser printer and had recognized the need for a standard means of defining page images. In 1975–76 Bob Sproull and William Newman developed the Press format, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalable Vector Graphics
Scalable Vector Graphics (SVG) is an XML-based vector graphics format for defining two-dimensional graphics, having support for interactivity and animation. The SVG specification is an open standard developed by the World Wide Web Consortium since 1999. SVG images are defined in a vector graphics format and stored in XML text files. SVG images can thus be scaled in size without loss of quality, and SVG files can be searched, indexed, scripted, and compressed. The XML text files can be created and edited with text editors or vector graphics editors, and are rendered by most web browsers. If used for images, SVG can host scripts or CSS, potentially leading to cross-site scripting attacks or other security vulnerabilities. History SVG has been in development within the World Wide Web Consortium (W3C) since 1999 after six competing proposals for vector graphics languages had been submitted to the consortium during 1998 (see below). The early SVG Working Group decided not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undirected Graph
In discrete mathematics, particularly in graph theory, a graph is a structure consisting of a set of objects where some pairs of the objects are in some sense "related". The objects are represented by abstractions called '' vertices'' (also called ''nodes'' or ''points'') and each of the related pairs of vertices is called an ''edge'' (also called ''link'' or ''line''). Typically, a graph is depicted in diagrammatic form as a set of dots or circles for the vertices, joined by lines or curves for the edges. The edges may be directed or undirected. For example, if the vertices represent people at a party, and there is an edge between two people if they shake hands, then this graph is undirected because any person ''A'' can shake hands with a person ''B'' only if ''B'' also shakes hands with ''A''. In contrast, if an edge from a person ''A'' to a person ''B'' means that ''A'' owes money to ''B'', then this graph is directed, because owing money is not necessarily reciprocated. Gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring System
In engineering and physics, a spring system or spring network is a model of physics described as a graph with a position at each vertex and a spring of given stiffness and length along each edge. This generalizes Hooke's law to higher dimensions. This simple model can be used to solve the pose of static systems from crystal lattice to springs. A spring system can be thought of as the simplest case of the finite element method for solving problems in statics. Assuming linear springs and small deformation (or restricting to one-dimensional motion) a spring system can be cast as a (possibly overdetermined) system of linear equations or equivalently as an energy minimization problem. Known spring lengths Consider the simple case of three nodes, in one dimension \mathbf = \begin x_1 \\ x_2 \\ x_3 \end, connected by two springs. If the nominal lengths, ''L'', of the springs are known to be 1 and 2 units respectively, i.e. \mathbf = \begin 1\\ 2 \end, then the system can be solved as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT&T Labs
AT&T Labs, Inc. (formerly AT&T Laboratories, Inc.) is the research & development division of AT&T, the telecommunications company. It employs some 1,800 people in various locations, including: Bedminster, New Jersey; Middletown Township, New Jersey, Middletown, New Jersey; Manhattan, New York; Warrenville, Illinois; Austin, Texas; Dallas, Texas; Atlanta, Georgia; San Francisco, California; San Ramon, California; and Redmond, Washington. The main research division, made up of around 450 people, is based across the Bedminster, Middletown, San Francisco, and Manhattan locations. AT&T Labs traces its history from Bell Labs, AT&T Bell Labs. Much research is in areas traditionally associated with networks and systems, ranging from the physics of optical transmission to foundational topics in computing and communications. Other research areas address the technical challenges of large operational networks and the resulting large data sets. Achievements Researchers at AT&T Labs wrot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Command-line Interface
A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user-friendly alternative to the non-interactive mode available with punched cards. For a long time, a CLI was the most common interface for software, but today a graphical user interface (GUI) is more common. Nonetheless, many programs such as operating system and software development utility software, utilities still provide CLI. A CLI enables automation, automating computer program, programs since commands can be stored in a scripting language, script computer file, file that can be used repeatedly. A script allows its contained commands to be executed as group; as a program; as a command. A CLI is made possible by command-line interpreters or command-line processors, which are programs that execute input commands. Alternatives to a CLI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
