Package edu.uci.ics.jung.graph

Class AbstractGraph<V,E>

java.lang.Object
edu.uci.ics.jung.graph.AbstractGraph<V,E>
All Implemented Interfaces:
Graph<V,E>, Hypergraph<V,E>, Serializable
Direct Known Subclasses:
AbstractTypedGraph, SparseGraph, SparseMultigraph
public abstract class AbstractGraph<V,E> extends Object implements Graph<V,E>, Serializable
Abstract implementation of the Graph interface. Designed to simplify implementation of new graph classes.
Author:
Joshua O'Madadhain
See Also:

  • Constructor Details

    • AbstractGraph

      public AbstractGraph()

  • Method Details

    • addEdge

      public boolean addEdge(E edge, Collection<? extends V> vertices)
      Description copied from interface: Hypergraph
      Adds edge to this graph. Fails under the following circumstances:
      • edge is already an element of the graph
      • either edge or vertices is null
      • vertices has the wrong number of vertices for the graph type
      • vertices are already connected by another edge in this graph, and this graph does not accept parallel edges
      Specified by:
      addEdge in interface Hypergraph<V,E>
      Parameters:
      edge - the edge to add
      vertices - the vertices to which the edge will be connected
      Returns:
      true if the add is successful, and false otherwise

    • addEdge

      public boolean addEdge(E edge, Collection<? extends V> vertices, EdgeType edgeType)
      Description copied from interface: Hypergraph
      Adds edge to this graph with type edge_type. Fails under the following circumstances:
      • edge is already an element of the graph
      • either edge or vertices is null
      • vertices has the wrong number of vertices for the graph type
      • vertices are already connected by another edge in this graph, and this graph does not accept parallel edges
      • edge_type is not legal for this graph
      Specified by:
      addEdge in interface Hypergraph<V,E>
      Parameters:
      edge - edge to add to this graph
      vertices - vertices which are to be connected by this edge
      edgeType - type of edge to add
      Returns:
      true if the add is successful, and false otherwise

    • addEdge

      public boolean addEdge(E e, V v1, V v2)
      Description copied from interface: Graph
      Adds edge e to this graph such that it connects vertex v1 to v2. Equivalent to addEdge(e, new Pair(v1, v2)). If this graph does not contain v1, v2, or both, implementations may choose to either silently add the vertices to the graph or throw an IllegalArgumentException. If this graph assigns edge types to its edges, the edge type of e will be the default for this graph. See Hypergraph.addEdge() for a listing of possible reasons for failure.
      Specified by:
      addEdge in interface Graph<V,E>
      Parameters:
      e - the edge to be added
      v1 - the first vertex to be connected
      v2 - the second vertex to be connected
      Returns:
      true if the add is successful, false otherwise
      See Also:

    • addEdge

      public boolean addEdge(E e, V v1, V v2, EdgeType edge_type)
      Description copied from interface: Graph
      Adds edge e to this graph such that it connects vertex v1 to v2. Equivalent to addEdge(e, new Pair(v1, v2)). If this graph does not contain v1, v2, or both, implementations may choose to either silently add the vertices to the graph or throw an IllegalArgumentException. If edgeType is not legal for this graph, this method will throw IllegalArgumentException. See Hypergraph.addEdge() for a listing of possible reasons for failure.
      Specified by:
      addEdge in interface Graph<V,E>
      Parameters:
      e - the edge to be added
      v1 - the first vertex to be connected
      v2 - the second vertex to be connected
      edge_type - the type to be assigned to the edge
      Returns:
      true if the add is successful, false otherwise
      See Also:

    • addEdge

      public boolean addEdge(E edge, Pair<? extends V> endpoints)
      Adds edge to this graph with the specified endpoints, with the default edge type.
      Parameters:
      edge - the edge to be added
      endpoints - the endpoints to be connected to this edge
      Returns:
      true iff the graph was modified as a result of this call

    • addEdge

      public abstract boolean addEdge(E edge, Pair<? extends V> endpoints, EdgeType edgeType)
      Adds edge to this graph with the specified endpoints and EdgeType.
      Parameters:
      edge - the edge to be added
      endpoints - the endpoints to be connected to this edge
      edgeType - the type of edge to add
      Returns:
      true iff the graph was modified as a result of this call

    • getValidatedEndpoints

      protected Pair<V> getValidatedEndpoints(E edge, Pair<? extends V> endpoints)

    • inDegree

      public int inDegree(V vertex)
      Description copied from interface: Graph
      Returns the number of incoming edges incident to vertex. Equivalent to getInEdges(vertex).size().
      Specified by:
      inDegree in interface Graph<V,E>
      Specified by:
      inDegree in interface Hypergraph<V,E>
      Parameters:
      vertex - the vertex whose indegree is to be calculated
      Returns:
      the number of incoming edges incident to vertex

    • outDegree

      public int outDegree(V vertex)
      Description copied from interface: Graph
      Returns the number of outgoing edges incident to vertex. Equivalent to getOutEdges(vertex).size().
      Specified by:
      outDegree in interface Graph<V,E>
      Specified by:
      outDegree in interface Hypergraph<V,E>
      Parameters:
      vertex - the vertex whose outdegree is to be calculated
      Returns:
      the number of outgoing edges incident to vertex

    • isPredecessor

      public boolean isPredecessor(V v1, V v2)
      Description copied from interface: Graph
      Returns true if v1 is a predecessor of v2 in this graph. Equivalent to v1.getPredecessors().contains(v2).
      Specified by:
      isPredecessor in interface Graph<V,E>
      Parameters:
      v1 - the first vertex to be queried
      v2 - the second vertex to be queried
      Returns:
      true if v1 is a predecessor of v2, and false otherwise.

    • isSuccessor

      public boolean isSuccessor(V v1, V v2)
      Description copied from interface: Graph
      Returns true if v1 is a successor of v2 in this graph. Equivalent to v1.getSuccessors().contains(v2).
      Specified by:
      isSuccessor in interface Graph<V,E>
      Parameters:
      v1 - the first vertex to be queried
      v2 - the second vertex to be queried
      Returns:
      true if v1 is a successor of v2, and false otherwise.

    • getPredecessorCount

      public int getPredecessorCount(V vertex)
      Description copied from interface: Graph
      Returns the number of predecessors that vertex has in this graph. Equivalent to vertex.getPredecessors().size().
      Specified by:
      getPredecessorCount in interface Graph<V,E>
      Parameters:
      vertex - the vertex whose predecessor count is to be returned
      Returns:
      the number of predecessors that vertex has in this graph

    • getSuccessorCount

      public int getSuccessorCount(V vertex)
      Description copied from interface: Graph
      Returns the number of successors that vertex has in this graph. Equivalent to vertex.getSuccessors().size().
      Specified by:
      getSuccessorCount in interface Graph<V,E>
      Parameters:
      vertex - the vertex whose successor count is to be returned
      Returns:
      the number of successors that vertex has in this graph

    • isNeighbor

      public boolean isNeighbor(V v1, V v2)
      Description copied from interface: Hypergraph
      Returns true if v1 and v2 share an incident edge. Equivalent to getNeighbors(v1).contains(v2).
      Specified by:
      isNeighbor in interface Hypergraph<V,E>
      Parameters:
      v1 - the first vertex to test
      v2 - the second vertex to test
      Returns:
      true if v1 and v2 share an incident edge

    • isIncident

      public boolean isIncident(V vertex, E edge)
      Description copied from interface: Hypergraph
      Returns true if vertex and edge are incident to each other. Equivalent to getIncidentEdges(vertex).contains(edge) and to getIncidentVertices(edge).contains(vertex).
      Specified by:
      isIncident in interface Hypergraph<V,E>
      Parameters:
      vertex - vertex to test
      edge - edge to test
      Returns:
      true if vertex and edge are incident to each other

    • getNeighborCount

      public int getNeighborCount(V vertex)
      Description copied from interface: Hypergraph
      Returns the number of vertices that are adjacent to vertex (that is, the number of vertices that are incident to edges in vertex's incident edge set).

      Equivalent to getNeighbors(vertex).size().

      Specified by:
      getNeighborCount in interface Hypergraph<V,E>
      Parameters:
      vertex - the vertex whose neighbor count is to be returned
      Returns:
      the number of neighboring vertices

    • degree

      public int degree(V vertex)
      Description copied from interface: Hypergraph
      Returns the number of edges incident to vertex. Special cases of interest:
      • Incident self-loops are counted once.
      • If there is only one edge that connects this vertex to each of its neighbors (and vice versa), then the value returned will also be equal to the number of neighbors that this vertex has (that is, the output of getNeighborCount).
      • If the graph is directed, then the value returned will be the sum of this vertex's indegree (the number of edges whose destination is this vertex) and its outdegree (the number of edges whose source is this vertex), minus the number of incident self-loops (to avoid double-counting).

      Equivalent to getIncidentEdges(vertex).size().

      Specified by:
      degree in interface Hypergraph<V,E>
      Parameters:
      vertex - the vertex whose degree is to be returned
      Returns:
      the degree of this node
      See Also:

    • getIncidentCount

      public int getIncidentCount(E edge)
      Description copied from interface: Hypergraph
      Returns the number of vertices that are incident to edge. For hyperedges, this can be any nonnegative integer; for edges this must be 2 (or 1 if self-loops are permitted).

      Equivalent to getIncidentVertices(edge).size().

      Specified by:
      getIncidentCount in interface Hypergraph<V,E>
      Parameters:
      edge - the edge whose incident vertex count is to be returned
      Returns:
      the number of vertices that are incident to edge.

    • getOpposite

      public V getOpposite(V vertex, E edge)
      Description copied from interface: Graph
      Returns the vertex at the other end of edge from vertex. (That is, returns the vertex incident to edge which is not vertex.)
      Specified by:
      getOpposite in interface Graph<V,E>
      Parameters:
      vertex - the vertex to be queried
      edge - the edge to be queried
      Returns:
      the vertex at the other end of edge from vertex

    • findEdge

      public E findEdge(V v1, V v2)
      Description copied from interface: Hypergraph
      Returns an edge that connects this vertex to v. If this edge is not uniquely defined (that is, if the graph contains more than one edge connecting v1 to v2), any of these edges may be returned. findEdgeSet(v1, v2) may be used to return all such edges. Returns null if either of the following is true:
      • v2 is not connected to v1
      • either v1 or v2 are not present in this graph

      Note: for purposes of this method, v1 is only considered to be connected to v2 via a given directed edge e if v1 == e.getSource() && v2 == e.getDest() evaluates to true. (v1 and v2 are connected by an undirected edge u if u is incident to both v1 and v2.)

      Specified by:
      findEdge in interface Hypergraph<V,E>
      Parameters:
      v1 - the first endpoint of the returned edge
      v2 - the second endpoint of the returned edge
      Returns:
      an edge that connects v1 to v2, or null if no such edge exists (or either vertex is not present)
      See Also:

    • findEdgeSet

      public Collection<E> findEdgeSet(V v1, V v2)
      Description copied from interface: Hypergraph
      Returns all edges that connects this vertex to v. If this edge is not uniquely defined (that is, if the graph contains more than one edge connecting v1 to v2), any of these edges may be returned. findEdgeSet(v1, v2) may be used to return all such edges. Returns null if v2 is not connected to v1.
      Returns an empty collection if either v1 or v2 are not present in this graph.

      Note: for purposes of this method, v1 is only considered to be connected to v2 via a given directed edge d if v1 == d.getSource() && v2 == d.getDest() evaluates to true. (v1 and v2 are connected by an undirected edge u if u is incident to both v1 and v2.)

      Specified by:
      findEdgeSet in interface Hypergraph<V,E>
      Parameters:
      v1 - the first endpoint of the returned edge set
      v2 - the second endpoint of the returned edge set
      Returns:
      a collection containing all edges that connect v1 to v2, or null if either vertex is not present
      See Also:

    • getIncidentVertices

      public Collection<V> getIncidentVertices(E edge)
      Description copied from interface: Hypergraph
      Returns the collection of vertices in this graph which are connected to edge. Note that for some graph types there are guarantees about the size of this collection (i.e., some graphs contain edges that have exactly two endpoints, which may or may not be distinct). Implementations for those graph types may provide alternate methods that provide more convenient access to the vertices.
      Specified by:
      getIncidentVertices in interface Hypergraph<V,E>
      Parameters:
      edge - the edge whose incident vertices are to be returned
      Returns:
      the collection of vertices which are connected to edge, or null if edge is not present

    • toString

      public String toString()
      Overrides:
      toString in class Object