Interface Network<N,​E>

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      Set<E> adjacentEdges​(E edge)
      Returns the edges which have an incident node in common with edge.
      Set<N> adjacentNodes​(N node)
      Returns the nodes which have an incident edge in common with node in this network.
      boolean allowsParallelEdges()
      Returns true if this network allows parallel edges.
      boolean allowsSelfLoops()
      Returns true if this network allows self-loops (edges that connect a node to itself).
      Graph<N> asGraph()
      Returns a live view of this network as a Graph.
      int degree​(N node)
      Returns the count of node's incident edges, counting self-loops twice (equivalently, the number of times an edge touches node).
      Optional<E> edgeConnecting​(EndpointPair<N> endpoints)
      Returns the single edge that directly connects endpoints (in the order, if any, specified by endpoints), if one is present, or Optional.empty() if no such edge exists.
      Optional<E> edgeConnecting​(N nodeU, N nodeV)
      Returns the single edge that directly connects nodeU to nodeV, if one is present, or Optional.empty() if no such edge exists.
      @Nullable E edgeConnectingOrNull​(EndpointPair<N> endpoints)
      Returns the single edge that directly connects endpoints (in the order, if any, specified by endpoints), if one is present, or null if no such edge exists.
      @Nullable E edgeConnectingOrNull​(N nodeU, N nodeV)
      Returns the single edge that directly connects nodeU to nodeV, if one is present, or null if no such edge exists.
      ElementOrder<E> edgeOrder()
      Returns the order of iteration for the elements of edges().
      Set<E> edges()
      Returns all edges in this network, in the order specified by edgeOrder().
      Set<E> edgesConnecting​(EndpointPair<N> endpoints)
      Returns the set of edges that each directly connect endpoints (in the order, if any, specified by endpoints).
      Set<E> edgesConnecting​(N nodeU, N nodeV)
      Returns the set of edges that each directly connect nodeU to nodeV.
      boolean equals​(@Nullable Object object)
      Returns true iff object is a Network that has the same elements and the same structural relationships as those in this network.
      boolean hasEdgeConnecting​(EndpointPair<N> endpoints)
      Returns true if there is an edge that directly connects endpoints (in the order, if any, specified by endpoints).
      boolean hasEdgeConnecting​(N nodeU, N nodeV)
      Returns true if there is an edge that directly connects nodeU to nodeV.
      int hashCode()
      Returns the hash code for this network.
      Set<E> incidentEdges​(N node)
      Returns the edges whose incident nodes in this network include node.
      EndpointPair<N> incidentNodes​(E edge)
      Returns the nodes which are the endpoints of edge in this network.
      int inDegree​(N node)
      Returns the count of node's incoming edges in a directed network.
      Set<E> inEdges​(N node)
      Returns all edges in this network which can be traversed in the direction (if any) of the edge to end at node.
      boolean isDirected()
      Returns true if the edges in this network are directed.
      ElementOrder<N> nodeOrder()
      Returns the order of iteration for the elements of nodes().
      Set<N> nodes()
      Returns all nodes in this network, in the order specified by nodeOrder().
      int outDegree​(N node)
      Returns the count of node's outgoing edges in a directed network.
      Set<E> outEdges​(N node)
      Returns all edges in this network which can be traversed in the direction (if any) of the edge starting from node.
      Set<N> predecessors​(N node)
      Returns all nodes in this network adjacent to node which can be reached by traversing node's incoming edges against the direction (if any) of the edge.
      Set<N> successors​(N node)
      Returns all nodes in this network adjacent to node which can be reached by traversing node's outgoing edges in the direction (if any) of the edge.
    • Method Detail

      • asGraph

        Graph<NasGraph()
        Returns a live view of this network as a Graph. The resulting Graph will have an edge connecting node A to node B if this Network has an edge connecting A to B.

        If this network allows parallel edges, parallel edges will be treated as if collapsed into a single edge. For example, the degree(Object) of a node in the Graph view may be less than the degree of the same node in this Network.

      • isDirected

        boolean isDirected()
        Returns true if the edges in this network are directed. Directed edges connect a source node to a target node, while undirected edges connect a pair of nodes to each other.
      • allowsParallelEdges

        boolean allowsParallelEdges()
        Returns true if this network allows parallel edges. Attempting to add a parallel edge to a network that does not allow them will throw an IllegalArgumentException.
      • allowsSelfLoops

        boolean allowsSelfLoops()
        Returns true if this network allows self-loops (edges that connect a node to itself). Attempting to add a self-loop to a network that does not allow them will throw an IllegalArgumentException.
      • degree

        int degree​(N node)
        Returns the count of node's incident edges, counting self-loops twice (equivalently, the number of times an edge touches node).

        For directed networks, this is equal to inDegree(node) + outDegree(node).

        For undirected networks, this is equal to incidentEdges(node).size() + (number of self-loops incident to node).

        If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

        Throws:
        IllegalArgumentException - if node is not an element of this network
      • inDegree

        int inDegree​(N node)
        Returns the count of node's incoming edges in a directed network. In an undirected network, returns the degree(Object).

        If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

        Throws:
        IllegalArgumentException - if node is not an element of this network
      • outDegree

        int outDegree​(N node)
        Returns the count of node's outgoing edges in a directed network. In an undirected network, returns the degree(Object).

        If the count is greater than Integer.MAX_VALUE, returns Integer.MAX_VALUE.

        Throws:
        IllegalArgumentException - if node is not an element of this network
      • edgesConnecting

        Set<EedgesConnecting​(N nodeU,
                               N nodeV)
        Returns the set of edges that each directly connect nodeU to nodeV.

        In an undirected network, this is equal to edgesConnecting(nodeV, nodeU).

        The resulting set of edges will be parallel (i.e. have equal incidentNodes(Object). If this network does not allow parallel edges, the resulting set will contain at most one edge (equivalent to edgeConnecting(nodeU, nodeV).asSet()).

        Throws:
        IllegalArgumentException - if nodeU or nodeV is not an element of this network
      • edgesConnecting

        Set<EedgesConnecting​(EndpointPair<N> endpoints)
        Returns the set of edges that each directly connect endpoints (in the order, if any, specified by endpoints).

        The resulting set of edges will be parallel (i.e. have equal incidentNodes(Object). If this network does not allow parallel edges, the resulting set will contain at most one edge (equivalent to edgeConnecting(endpoints).asSet()).

        If this network is directed, endpoints must be ordered.

        Throws:
        IllegalArgumentException - if either endpoint is not an element of this network
        IllegalArgumentException - if the endpoints are unordered and the graph is directed
        Since:
        27.1
      • edgeConnecting

        Optional<EedgeConnecting​(N nodeU,
                                   N nodeV)
        Returns the single edge that directly connects nodeU to nodeV, if one is present, or Optional.empty() if no such edge exists.

        In an undirected network, this is equal to edgeConnecting(nodeV, nodeU).

        Throws:
        IllegalArgumentException - if there are multiple parallel edges connecting nodeU to nodeV
        IllegalArgumentException - if nodeU or nodeV is not an element of this network
        Since:
        23.0
      • edgeConnecting

        Optional<EedgeConnecting​(EndpointPair<N> endpoints)
        Returns the single edge that directly connects endpoints (in the order, if any, specified by endpoints), if one is present, or Optional.empty() if no such edge exists.

        If this graph is directed, the endpoints must be ordered.

        Throws:
        IllegalArgumentException - if there are multiple parallel edges connecting nodeU to nodeV
        IllegalArgumentException - if either endpoint is not an element of this network
        IllegalArgumentException - if the endpoints are unordered and the graph is directed
        Since:
        27.1
      • edgeConnectingOrNull

        @Nullable E edgeConnectingOrNull​(N nodeU,
                                         N nodeV)
        Returns the single edge that directly connects nodeU to nodeV, if one is present, or null if no such edge exists.

        In an undirected network, this is equal to edgeConnectingOrNull(nodeV, nodeU).

        Throws:
        IllegalArgumentException - if there are multiple parallel edges connecting nodeU to nodeV
        IllegalArgumentException - if nodeU or nodeV is not an element of this network
        Since:
        23.0
      • edgeConnectingOrNull

        @Nullable E edgeConnectingOrNull​(EndpointPair<N> endpoints)
        Returns the single edge that directly connects endpoints (in the order, if any, specified by endpoints), if one is present, or null if no such edge exists.

        If this graph is directed, the endpoints must be ordered.

        Throws:
        IllegalArgumentException - if there are multiple parallel edges connecting nodeU to nodeV
        IllegalArgumentException - if either endpoint is not an element of this network
        IllegalArgumentException - if the endpoints are unordered and the graph is directed
        Since:
        27.1
      • hasEdgeConnecting

        boolean hasEdgeConnecting​(N nodeU,
                                  N nodeV)
        Returns true if there is an edge that directly connects nodeU to nodeV. This is equivalent to nodes().contains(nodeU) && successors(nodeU).contains(nodeV), and to edgeConnectingOrNull(nodeU, nodeV) != null.

        In an undirected graph, this is equal to hasEdgeConnecting(nodeV, nodeU).

        Since:
        23.0
      • equals

        boolean equals​(@Nullable Object object)
        Returns true iff object is a Network that has the same elements and the same structural relationships as those in this network.

        Thus, two networks A and B are equal if all of the following are true:

        • A and B have equal directedness.
        • A and B have equal node sets.
        • A and B have equal edge sets.
        • Every edge in A and B connects the same nodes in the same direction (if any).

        Network properties besides directedness do not affect equality. For example, two networks may be considered equal even if one allows parallel edges and the other doesn't. Additionally, the order in which nodes or edges are added to the network, and the order in which they are iterated over, are irrelevant.

        A reference implementation of this is provided by AbstractNetwork.equals(Object).

        Overrides:
        equals in class Object
        Parameters:
        object - the reference object with which to compare.
        Returns:
        true if this object is the same as the obj argument; false otherwise.
        See Also:
        Object.hashCode(), HashMap