Package net.sf.tweety.graphs

Interface Graph<T extends Node>

  • Type Parameters:
    T - The type of the node.
    All Superinterfaces:
    Iterable<T>
    All Known Implementing Classes:
    DefaultGraph
    public interface Graph<T extends Node>
extends Iterable<T>
    Common interface for graphs with nodes of type T
    Author:
    Matthias Thimm

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static int IGNORE_SELFLOOPS
      When inverting a graph, ignore self loops (don't add and don't remove)
      static int INVERT_SELFLOOPS
      When inverting a graph, deal with self loops like ordinary edges (add if not present and remove if present)
      static int REMOVE_SELFLOOPS
      When inverting a graph, simple remove self loops, but don't add new ones.

    • Field Detail

      • IGNORE_SELFLOOPS

        static final int IGNORE_SELFLOOPS
        When inverting a graph, ignore self loops (don't add and don't remove)
        See Also:
        Constant Field Values

      • INVERT_SELFLOOPS

        static final int INVERT_SELFLOOPS
        When inverting a graph, deal with self loops like ordinary edges (add if not present and remove if present)
        See Also:
        Constant Field Values

      • REMOVE_SELFLOOPS

        static final int REMOVE_SELFLOOPS
        When inverting a graph, simple remove self loops, but don't add new ones.
        See Also:
        Constant Field Values

    • Method Detail

      • add

        boolean add​(T node)
        Adds the given node to this graph.
        Parameters:
        node - some node.
        Returns:
        "true" iff the edge has been added successfully.

      • add

        boolean add​(Edge<T> edge)
        Adds the given edge to this graph. If at least one of the nodes the given edge connects is not in the graph, an illegal argument exception is thrown.
        Parameters:
        edge - some edge.
        Returns:
        "true" iff the edge has been added successfully.

      • getNodes

        Collection<T> getNodes()
        Returns the nodes of this graph.
        Returns:
        the nodes of this graph.

      • getNumberOfNodes

        int getNumberOfNodes()
        Returns the number of nodes in this graph.
        Returns:
        the number of nodes in this graph.

      • areAdjacent

        boolean areAdjacent​(T a,
                    T b)
        Returns "true" iff the two nodes are connected by a directed edge from a to b or an undirected edge.
        Parameters:
        a - some node
        b - some node
        Returns:
        "true" iff the two nodes are connected by a directed edge from a to b or an undirected edge.

      • getEdge

        Edge<T> getEdge​(T a,
                T b)
        Returns the corresponding edge (a,b) if a and b are adjacent. Otherwise it returns null.
        Parameters:
        a - some node
        b - some node
        Returns:
        the edge (a,b) or null.

      • getEdges

        Collection<? extends Edge<? extends T>> getEdges()
        Returns the edges of this graph.
        Returns:
        the edges of this graph.

      • contains

        boolean contains​(Object obj)
        Returns "true" when this graph contains the given node or edge.
        Parameters:
        obj - an object
        Returns:
        "true" if this graph contains the given node or edge.

      • getChildren

        Collection<T> getChildren​(Node node)
        Returns the set of children (node connected via an undirected edge or a directed edge where the given node is the parent) of the given node.
        Parameters:
        node - some node (must be in the graph).
        Returns:
        the set of children of the given node.

      • getParents

        Collection<T> getParents​(Node node)
        Returns the set of parents (node connected via an undirected edge or a directed edge where the given node is the child) of the given node.
        Parameters:
        node - some node (must be in the graph).
        Returns:
        the set of parents of the given node.

      • existsDirectedPath

        boolean existsDirectedPath​(T node1,
                           T node2)
        Checks whether there is a (directed) path from node1 to node2.
        Parameters:
        node1 - some node.
        node2 - some node.
        Returns:
        "true" if there is a directed path from node1 to node2.

      • getNeighbors

        Collection<T> getNeighbors​(T node)
        Returns the set of neighbors of the given node.
        Parameters:
        node - some node (must be in the graph).
        Returns:
        the set of neighbors of the given node.

      • getAdjacencyMatrix

        net.sf.tweety.math.matrix.Matrix getAdjacencyMatrix()
        Returns the adjacency matrix of this graph (the order of the nodes is the same as returned by "iterator()").
        Returns:
        the adjacency matrix of this graph

      • getComplementGraph

        Graph<T> getComplementGraph​(int selfloops)
        Returns the complement graph of this graph, i.e. the graph on the same set of vertices as this graph that connects two vertices v and w with an edge if and only if v and w are not connected in this graph.
        Parameters:
        selfloops - Indicates how to deal with selfloops:
        IGNORE_SELFLOOPS - ignore self loops (don't add and don't remove)
        INVERT_SELFLOOPS - deal with self loops like ordinary edges (add if not present and remove if present)
        REMOVE_SELFLOOPS - simple remove self loops, but don't add new ones.
        Returns:
        the complement graph of this graph.

      • getStronglyConnectedComponents

        Collection<Collection<T>> getStronglyConnectedComponents()
        Returns the strongly connected components of this graph. A set of nodes is strongly connected, if there is a path from each node to each other. A set of nodes is called strongly connected component if it is strongly connected and maximal with respect to set inclusion.
        Returns:
        the strongly connected components of this graph.

      • getSubgraphs

        Collection<Graph<T>> getSubgraphs()
        Returns the set of sub graphs of this graph.
        Returns:
        the set of sub graphs of this graph.

      • getRestriction

        Graph<T> getRestriction​(Collection<T> nodes)
        Returns copy of this graph consisting only of the given nodes and all corresponding edges.
        Parameters:
        nodes - a set of nodes
        Returns:
        a graph.

      • hasSelfLoops

        boolean hasSelfLoops()
        Returns "true" iff the graph has a self loop (an edge from a node to itself).
        Returns:
        "true" iff the graph has a self loop (an edge from a node to itself).

      • isWeightedGraph

        boolean isWeightedGraph()
        Checks whether this graph only contains weighted edges.
        Returns:
        "true" if all edges are weighted in this graph.