GraphML

GraphML is an XML -based file format for representing graphs . GraphML consists of a language core for describing the structure of a graph and an extension mechanism for application-specific data. GraphML is a free file format based on the Creative Commons Attribution 3.0 license.

history

The GraphML project was started by the Graph Drawing Steering Committee in advance of the Graph Drawing 2000 conference in Williamsburg, Virginia . The forerunner of GraphML was the Graph Modeling Language (GML), which was started on the basis of an initiative of the Graph Drawing 1995 conference in Passau .

functionality

Undirected graph generated from the code

GraphML supports directed , undirected and mixed graphs, hypergraphs and hierarchical graphs. It offers options for describing the graphic representation of the graph, references to external data and application-specific attributes.

The simple undirected graph with four nodes and four edges shown on the right looks like this in GraphML:

<?xml version="1.0" encoding="UTF-8"?>
<graphml xmlns="http://graphml.graphdrawing.org/xmlns"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns
     http://graphml.graphdrawing.org/xmlns/1.0/graphml.xsd">
  <graph id="G" edgedefault="undirected">
    <node id="A"/>
    <node id="B"/>
    <node id="C"/>
    <node id="D"/>
    <edge id="ab" source="A" target="B"/>
    <edge id="bc" source="B" target="C"/>
    <edge id="cd" source="C" target="D"/>
    <edge id="da" source="D" target="A"/>
  </graph>
</graphml>

Other file formats for graphs

• Graph Exchange Language (GXL) - another XML-based description language for graphs.
• Trivial Graph Format - simple text-based format for describing graphs.
• Graph Modeling Language (GML)
• eXtensible Graph Markup and Modeling Language (XGMML) - XML-based Graph Markup Language similar to GML.
• DOT - description language for graphs for the Graphviz tools.

See also

• XML
• Scalable Vector Graphics (SVG) - an XML-based file format for any graphics.
• yEd - a graphical editor for graphs based on the GraphML file format.

literature

• Ulrik Brandes, Markus Eiglsperger, Ivan Herman, Michael Himsolt, M. Scott Marshall: GraphML Progress Report . Structural Layer Proposal. In: Department of Computer & Information Science, University of Konstanz (Ed.): Proceedings 9th International Symposium on Graph Drawing (GD '01) . Springer-Verlag, 2002, p. 501–512 (English, uni-konstanz.de (Ghostscript, gzipped) [accessed on August 3, 2010]).

Web links

• graphml.graphdrawing.org - Homepage of GraphML
• graphml.graphdrawing.org - Primer - Introduction to GraphML
• svgopen.org - Comparison between XML and SVG transformation mechanisms

Individual evidence

1. ↑ About GraphML