Class DIMACSImporter<V,​E>

  • Type Parameters:
    V - the graph vertex type
    E - the graph edge type
    All Implemented Interfaces:

    public class DIMACSImporter<V,​E>
    extends BaseEventDrivenImporter<V,​E>
    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).
    Michael Behrisch (adaptation of GraphReader class), Joris Kinable, Dimitrios Michail
    • Constructor Detail

      • DIMACSImporter

        public DIMACSImporter​(double defaultWeight)
        Construct a new DIMACSImporter
        defaultWeight - default edge weight
      • DIMACSImporter

        public DIMACSImporter()
        Construct a new DIMACSImporter
    • Method Detail

      • 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>
        graph - the output graph
        input - the input reader
        ImportException - in case an error occurs, such as I/O or parse error