Hypergraph (JUNG - API 2.1.1 API)

All Known Subinterfaces:

DirectedGraph<V,E>, Forest<V,E>, Graph<V,E>, KPartiteGraph<V,E>, Tree<V,E>, UndirectedGraph<V,E>

All Known Implementing Classes:

GraphDecorator, ObservableGraph
```
public interface Hypergraph<V,E>
```
A hypergraph, consisting of a set of vertices of type V and a set of hyperedges of type E which connect the vertices. This is the base interface for all JUNG graph types.
This interface permits, but does not enforce, any of the following common variations of graphs:
- hyperedges (edges which connect a set of vertices of any size)
- edges (these have have exactly two endpoints, which may or may not be distinct)
- self-loops (edges which connect exactly one vertex)
- directed and undirected edges
- vertices and edges with attributes (for example, weighted edges)
- vertices and edges with different constraints or properties (for example, bipartite or multimodal graphs)
- parallel edges (multiple edges which connect a single set of vertices)
- internal representations as matrices or as adjacency lists or adjacency maps
Extensions or implementations of this interface may enforce or disallow any or all of these variations.
Notes:
- The collections returned by Hypergraph instances should be treated in general as if read-only. While they are not contractually guaranteed (or required) to be immutable, this interface does not define the outcome if they are mutated. Mutations should be done via {add,remove}{Edge,Vertex}, or in the constructor.
Author:

Joshua O'Madadhain

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`boolean`	`addEdge(E edge, Collection<? extends V> vertices)` Adds `edge` to this graph.
`boolean`	`addEdge(E edge, Collection<? extends V> vertices, EdgeType edge_type)` Adds `edge` to this graph with type `edge_type`.
`boolean`	`addVertex(V vertex)` Adds `vertex` to this graph.
`boolean`	`containsEdge(E edge)` Returns true if this graph's edge collection contains `edge`.
`boolean`	`containsVertex(V vertex)` Returns true if this graph's vertex collection contains `vertex`.
`int`	`degree(V vertex)` Returns the number of edges incident to `vertex`.
`E`	`findEdge(V v1, V v2)` Returns an edge that connects this vertex to `v`.
`Collection<E>`	`findEdgeSet(V v1, V v2)` Returns all edges that connects this vertex to `v`.
`EdgeType`	`getDefaultEdgeType()` Returns the default edge type for this graph.
`V`	`getDest(E directed_edge)` If `directed_edge` is a directed edge in this graph, returns the destination; otherwise returns `null`.
`int`	`getEdgeCount()` Returns the number of edges in this graph.
`int`	`getEdgeCount(EdgeType edge_type)` Returns the number of edges of type `edge_type` in this graph.
`Collection<E>`	`getEdges()` Returns a view of all edges in this graph.
`Collection<E>`	`getEdges(EdgeType edge_type)` Returns the collection of edges in this graph which are of type `edge_type`.
`EdgeType`	`getEdgeType(E edge)` Returns the edge type of `edge` in this graph.
`int`	`getIncidentCount(E edge)` Returns the number of vertices that are incident to `edge`.
`Collection<E>`	`getIncidentEdges(V vertex)` Returns the collection of edges in this graph which are connected to `vertex`.
`Collection<V>`	`getIncidentVertices(E edge)` Returns the collection of vertices in this graph which are connected to `edge`.
`Collection<E>`	`getInEdges(V vertex)` Returns a `Collection` view of the incoming edges incident to `vertex` in this graph.
`int`	`getNeighborCount(V vertex)` 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).
`Collection<V>`	`getNeighbors(V vertex)` Returns the collection of vertices which are connected to `vertex` via any edges in this graph.
`Collection<E>`	`getOutEdges(V vertex)` Returns a `Collection` view of the outgoing edges incident to `vertex` in this graph.
`Collection<V>`	`getPredecessors(V vertex)` Returns a `Collection` view of the predecessors of `vertex` in this graph.
`V`	`getSource(E directed_edge)` If `directed_edge` is a directed edge in this graph, returns the source; otherwise returns `null`.
`Collection<V>`	`getSuccessors(V vertex)` Returns a `Collection` view of the successors of `vertex` in this graph.
`int`	`getVertexCount()` Returns the number of vertices in this graph.
`Collection<V>`	`getVertices()` Returns a view of all vertices in this graph.
`int`	`inDegree(V vertex)` Returns the number of incoming edges incident to `vertex`.
`boolean`	`isIncident(V vertex, E edge)` Returns `true` if `vertex` and `edge` are incident to each other.
`boolean`	`isNeighbor(V v1, V v2)` Returns `true` if `v1` and `v2` share an incident edge.
`int`	`outDegree(V vertex)` Returns the number of outgoing edges incident to `vertex`.
`boolean`	`removeEdge(E edge)` Removes `edge` from this graph.
`boolean`	`removeVertex(V vertex)` Removes `vertex` from this graph.

- Method Detail
  - getEdges
```
Collection<E> getEdges()
```
    Returns a view of all edges in this graph. In general, this obeys the Collection contract, and therefore makes no guarantees about the ordering of the vertices within the set.
    
    Returns:
    
    a Collection view of all edges in this graph
  - getVertices
```
Collection<V> getVertices()
```
    Returns a view of all vertices in this graph. In general, this obeys the Collection contract, and therefore makes no guarantees about the ordering of the vertices within the set.
    
    Returns:
    
    a Collection view of all vertices in this graph
  - containsVertex
```
boolean containsVertex(V vertex)
```
    Returns true if this graph's vertex collection contains vertex. Equivalent to getVertices().contains(vertex).
    
    Parameters:
    
    vertex - the vertex whose presence is being queried
    
    Returns:
    
    true iff this graph contains a vertex vertex
  - containsEdge
```
boolean containsEdge(E edge)
```
    Returns true if this graph's edge collection contains edge. Equivalent to getEdges().contains(edge).
    
    Parameters:
    
    edge - the edge whose presence is being queried
    
    Returns:
    
    true iff this graph contains an edge edge
  - getEdgeCount
```
int getEdgeCount()
```
    Returns the number of edges in this graph.
    
    Returns:
    
    the number of edges in this graph
  - getVertexCount
```
int getVertexCount()
```
    Returns the number of vertices in this graph.
    
    Returns:
    
    the number of vertices in this graph
  - getNeighbors
```
Collection<V> getNeighbors(V vertex)
```
    Returns the collection of vertices which are connected to vertex via any edges in this graph. If vertex is connected to itself with a self-loop, then it will be included in the collection returned.
    
    Parameters:
    
    vertex - the vertex whose neighbors are to be returned
    
    Returns:
    
    the collection of vertices which are connected to vertex, or null if vertex is not present
  - getIncidentEdges
```
Collection<E> getIncidentEdges(V vertex)
```
    Returns the collection of edges in this graph which are connected to vertex.
    
    Parameters:
    
    vertex - the vertex whose incident edges are to be returned
    
    Returns:
    
    the collection of edges which are connected to vertex, or null if vertex is not present
  - getIncidentVertices
```
Collection<V> getIncidentVertices(E edge)
```
    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.
    
    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
  - findEdge
```
E findEdge(V v1,
           V v2)
```
    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.)
    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(Object, Object)
  - findEdgeSet
```
Collection<E> findEdgeSet(V v1,
                          V v2)
```
    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.)
    
    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:
    
    findEdge(Object, Object)
  - addVertex
```
boolean addVertex(V vertex)
```
    Adds vertex to this graph. Fails if vertex is null or already in the graph.
    
    Parameters:
    
    vertex - the vertex to add
    
    Returns:
    
    true if the add is successful, and false otherwise
    
    Throws:
    
    IllegalArgumentException - if vertex is null
  - addEdge
```
boolean addEdge(E edge,
                Collection<? extends V> vertices)
```
    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
    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
    
    Throws:
    
    IllegalArgumentException - if edge or vertices is null, or if a different vertex set in this graph is already connected by edge, or if vertices are not a legal vertex set for edge
  - addEdge
```
boolean addEdge(E edge,
                Collection<? extends V> vertices,
                EdgeType edge_type)
```
    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
    Parameters:
    
    edge - edge to add to this graph
    
    vertices - vertices which are to be connected by this edge
    
    edge_type - type of edge to add
    
    Returns:
    
    true if the add is successful, and false otherwise
    
    Throws:
    
    IllegalArgumentException - if edge or vertices is null, or if a different vertex set in this graph is already connected by edge, or if vertices are not a legal vertex set for edge
  - removeVertex
```
boolean removeVertex(V vertex)
```
    Removes vertex from this graph. As a side effect, removes any edges e incident to vertex if the removal of vertex would cause e to be incident to an illegal number of vertices. (Thus, for example, incident hyperedges are not removed, but incident edges--which must be connected to a vertex at both endpoints--are removed.)
    Fails under the following circumstances:
    - vertex is not an element of this graph
    - vertex is null
    Parameters:
    
    vertex - the vertex to remove
    
    Returns:
    
    true if the removal is successful, false otherwise
  - removeEdge
```
boolean removeEdge(E edge)
```
    Removes edge from this graph. Fails if edge is null, or is otherwise not an element of this graph.
    
    Parameters:
    
    edge - the edge to remove
    
    Returns:
    
    true if the removal is successful, false otherwise
  - isNeighbor
```
boolean isNeighbor(V v1,
                   V v2)
```
    Returns true if v1 and v2 share an incident edge. Equivalent to getNeighbors(v1).contains(v2).
    
    Parameters:
    
    v1 - the first vertex to test
    
    v2 - the second vertex to test
    
    Returns:
    
    true if v1 and v2 share an incident edge
  - isIncident
```
boolean isIncident(V vertex,
                   E edge)
```
    Returns true if vertex and edge are incident to each other. Equivalent to getIncidentEdges(vertex).contains(edge) and to getIncidentVertices(edge).contains(vertex).
    
    Parameters:
    
    vertex - vertex to test
    
    edge - edge to test
    
    Returns:
    
    true if vertex and edge are incident to each other
  - degree
```
int degree(V vertex)
```
    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().
    Parameters:
    
    vertex - the vertex whose degree is to be returned
    
    Returns:
    
    the degree of this node
    
    See Also:
    
    getNeighborCount(Object)
  - getNeighborCount
```
int getNeighborCount(V vertex)
```
    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().
    
    Parameters:
    
    vertex - the vertex whose neighbor count is to be returned
    
    Returns:
    
    the number of neighboring vertices
  - getIncidentCount
```
int getIncidentCount(E edge)
```
    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().
    
    Parameters:
    
    edge - the edge whose incident vertex count is to be returned
    
    Returns:
    
    the number of vertices that are incident to edge.
  - getEdgeType
```
EdgeType getEdgeType(E edge)
```
    Returns the edge type of edge in this graph.
    
    Parameters:
    
    edge - the edge whose type is to be returned
    
    Returns:
    
    the EdgeType of edge, or null if edge has no defined type
  - getDefaultEdgeType
```
EdgeType getDefaultEdgeType()
```
    Returns the default edge type for this graph.
    
    Returns:
    
    the default edge type for this graph
  - getEdges
```
Collection<E> getEdges(EdgeType edge_type)
```
    Returns the collection of edges in this graph which are of type edge_type.
    
    Parameters:
    
    edge_type - the type of edges to be returned
    
    Returns:
    
    the collection of edges which are of type edge_type, or null if the graph does not accept edges of this type
    
    See Also:
    
    EdgeType
  - getEdgeCount
```
int getEdgeCount(EdgeType edge_type)
```
    Returns the number of edges of type edge_type in this graph.
    
    Parameters:
    
    edge_type - the type of edge for which the count is to be returned
    
    Returns:
    
    the number of edges of type edge_type in this graph
  - getInEdges
```
Collection<E> getInEdges(V vertex)
```
    Returns a Collection view of the incoming edges incident to vertex in this graph.
    
    Parameters:
    
    vertex - the vertex whose incoming edges are to be returned
    
    Returns:
    
    a Collection view of the incoming edges incident to vertex in this graph
  - getOutEdges
```
Collection<E> getOutEdges(V vertex)
```
    Returns a Collection view of the outgoing edges incident to vertex in this graph.
    
    Parameters:
    
    vertex - the vertex whose outgoing edges are to be returned
    
    Returns:
    
    a Collection view of the outgoing edges incident to vertex in this graph
  - inDegree
```
int inDegree(V vertex)
```
    Returns the number of incoming edges incident to vertex. Equivalent to getInEdges(vertex).size().
    
    Parameters:
    
    vertex - the vertex whose indegree is to be calculated
    
    Returns:
    
    the number of incoming edges incident to vertex
  - outDegree
```
int outDegree(V vertex)
```
    Returns the number of outgoing edges incident to vertex. Equivalent to getOutEdges(vertex).size().
    
    Parameters:
    
    vertex - the vertex whose outdegree is to be calculated
    
    Returns:
    
    the number of outgoing edges incident to vertex
  - getSource
```
V getSource(E directed_edge)
```
    If directed_edge is a directed edge in this graph, returns the source; otherwise returns null. The source of a directed edge d is defined to be the vertex for which d is an outgoing edge. directed_edge is guaranteed to be a directed edge if its EdgeType is DIRECTED.
    
    Parameters:
    
    directed_edge - the edge whose source is to be returned
    
    Returns:
    
    the source of directed_edge if it is a directed edge in this graph, or null otherwise
  - getDest
```
V getDest(E directed_edge)
```
    If directed_edge is a directed edge in this graph, returns the destination; otherwise returns null. The destination of a directed edge d is defined to be the vertex incident to d for which d is an incoming edge. directed_edge is guaranteed to be a directed edge if its EdgeType is DIRECTED.
    
    Parameters:
    
    directed_edge - the edge whose destination is to be returned
    
    Returns:
    
    the destination of directed_edge if it is a directed edge in this graph, or null otherwise
  - getPredecessors
```
Collection<V> getPredecessors(V vertex)
```
    Returns a Collection view of the predecessors of vertex in this graph. A predecessor of vertex is defined as a vertex v which is connected to vertex by an edge e, where e is an outgoing edge of v and an incoming edge of vertex.
    
    Parameters:
    
    vertex - the vertex whose predecessors are to be returned
    
    Returns:
    
    a Collection view of the predecessors of vertex in this graph
  - getSuccessors
```
Collection<V> getSuccessors(V vertex)
```
    Returns a Collection view of the successors of vertex in this graph. A successor of vertex is defined as a vertex v which is connected to vertex by an edge e, where e is an incoming edge of v and an outgoing edge of vertex.
    
    Parameters:
    
    vertex - the vertex whose predecessors are to be returned
    
    Returns:
    
    a Collection view of the successors of vertex in this graph

Interface Hypergraph<V,E>

Method Summary

Method Detail

getEdges

getVertices

containsVertex

containsEdge

getEdgeCount

getVertexCount

getNeighbors

getIncidentEdges

getIncidentVertices

findEdge

findEdgeSet

addVertex

addEdge

addEdge

removeVertex

removeEdge

isNeighbor

isIncident

degree

getNeighborCount

getIncidentCount

getEdgeType

getDefaultEdgeType

getEdges

getEdgeCount

getInEdges

getOutEdges

inDegree

outDegree

getSource

getDest

getPredecessors

getSuccessors