org.jgrapht.ext

Class DIMACSImporter<V,E>

java.lang.Object

org.jgrapht.ext.DIMACSImporter<V,E>

Type Parameters:

V - the graph vertex type

E - the graph edge type

All Implemented Interfaces:

GraphImporter<V,E>

public class DIMACSImporter<V,E>
extends Object
implements GraphImporter<V,E>

Imports a graph specified in DIMACS format.

See DIMACSFormat for a description of all the supported DIMACS formats.

In summary, one of the most common DIMACS formats was used in the 2nd DIMACS challenge and follows the following structure:

 
 DIMACS G {
    c <comments> ignored during parsing of the graph
    p edge <number of nodes> <number of edges>
    e <edge source 1> <edge target 1>
    e <edge source 2> <edge target 2>
    e <edge source 3> <edge target 3>
    e <edge source 4> <edge target 4>
    ...
 }
 
 

Although not specified directly in the DIMACS format documentation, this implementation also allows for the a weighted variant:

  
 e <edge source 1> <edge target 1> <edge_weight> 
 
 

Note: the current implementation does not fully implement the DIMACS specifications! Special (rarely used) fields specified as 'Optional Descriptors' are currently not supported (ignored).

Author:

Michael Behrisch (adaptation of GraphReader class), Joris Kinable, Dimitrios Michail

Constructor Summary

Constructors

Constructor and Description
DIMACSImporter(VertexProvider<V> vertexProvider, EdgeProvider<V,E> edgeProvider) Construct a new DIMACSImporter
DIMACSImporter(VertexProvider<V> vertexProvider, EdgeProvider<V,E> edgeProvider, double defaultWeight) Construct a new DIMACSImporter

Method Summary

Modifier and Type	Method and Description
EdgeProvider<V,E>	getEdgeProvider() Get the edge provider
VertexProvider<V>	getVertexProvider() Get the vertex provider
void	importGraph(Graph<V,E> graph, Reader input) Import a graph.
void	setEdgeProvider(EdgeProvider<V,E> edgeProvider) Set the edge provider.
void	setVertexProvider(VertexProvider<V> vertexProvider) Set the vertex provider

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.jgrapht.ext.GraphImporter

importGraph, importGraph

Constructor Detail

DIMACSImporter

public DIMACSImporter(VertexProvider<V> vertexProvider,
                      EdgeProvider<V,E> edgeProvider,
                      double defaultWeight)

Construct a new DIMACSImporter

Parameters:

vertexProvider - provider for the generation of vertices. Must not be null.

edgeProvider - provider for the generation of edges. Must not be null.

defaultWeight - default edge weight

DIMACSImporter

public DIMACSImporter(VertexProvider<V> vertexProvider,
                      EdgeProvider<V,E> edgeProvider)

Construct a new DIMACSImporter

Parameters:

vertexProvider - provider for the generation of vertices. Must not be null.

edgeProvider - provider for the generation of edges. Must not be null.

Method Detail

getVertexProvider

public VertexProvider<V> getVertexProvider()

Get the vertex provider

Returns:

the vertex provider

setVertexProvider

public void setVertexProvider(VertexProvider<V> vertexProvider)

Set the vertex provider

Parameters:

vertexProvider - the new vertex provider. Must not be null.

getEdgeProvider

public EdgeProvider<V,E> getEdgeProvider()

Get the edge provider

Returns:

The edge provider

setEdgeProvider

public void setEdgeProvider(EdgeProvider<V,E> edgeProvider)

Set the edge provider.

Parameters:

edgeProvider - the new edge provider. Must not be null.

importGraph

public void importGraph(Graph<V,E> graph,
                        Reader input)
                 throws ImportException

Import a graph.

The provided graph must be able to support the features of the graph that is read. For example if the file contains self-loops then the graph provided must also support self-loops. The same for multiple edges.

If the provided graph is a weighted graph, the importer also reads edge weights. Otherwise edge weights are ignored.

Specified by:

importGraph in interface GraphImporter<V,E>

Parameters:

graph - the output graph

input - the input reader

Throws:

ImportException - in case an error occurs, such as I/O or parse error