org.apache.flink.graph.bipartite

Class BipartiteGraph<KT,KB,VVT,VVB,EV>

java.lang.Object

org.apache.flink.graph.bipartite.BipartiteGraph<KT,KB,VVT,VVB,EV>

Type Parameters:

KT - the key type of top vertices

KB - the key type of bottom vertices

VVT - the vertex value type of top vertices

VVB - the vertex value type of bottom vertices

EV - the edge value type

public class BipartiteGraph<KT,KB,VVT,VVB,EV>
extends Object

The vertices of a bipartite graph are divided into two disjoint sets, referenced by the names "top" and "bottom". Top and bottom vertices with the same key value represent distinct entities and must be specially handled when projecting to a simple Graph. Edges can only exist between a pair of vertices from different vertices sets. E.g. there can be no vertices between a pair of top vertices.

Bipartite graphs are useful to represent graphs with two sets of objects, like researchers and their publications, where an edge represents that a particular publication was authored by a particular author.

Bipartite interface is different from Graph interface, so to apply algorithms that work on a regular graph a bipartite graph should be first converted into a Graph instance. This can be achieved by using the projection methods.

Method Summary

Modifier and Type	Method and Description
static <KT,KB,VVT,VVB,EV> BipartiteGraph<KT,KB,VVT,VVB,EV>	fromDataSet(DataSet<Vertex<KT,VVT>> topVertices, DataSet<Vertex<KB,VVB>> bottomVertices, DataSet<BipartiteEdge<KT,KB,EV>> edges, ExecutionEnvironment context) Create bipartite graph from datasets.
DataSet<Vertex<KB,VVB>>	getBottomVertices() Get dataset with bottom vertices.
DataSet<BipartiteEdge<KT,KB,EV>>	getEdges() Get dataset with graph edges.
DataSet<Vertex<KT,VVT>>	getTopVertices() Get dataset with top vertices.
Graph<KB,VVB,Projection<KT,VVT,VVB,EV>>	projectionBottomFull() Convert a bipartite graph into a graph that contains only bottom vertices.
Graph<KB,VVB,Tuple2<EV,EV>>	projectionBottomSimple() Convert a bipartite graph into an undirected graph that contains only bottom vertices.
Graph<KT,VVT,Projection<KB,VVB,VVT,EV>>	projectionTopFull() Convert a bipartite graph into a graph that contains only top vertices.
Graph<KT,VVT,Tuple2<EV,EV>>	projectionTopSimple() Convert a bipartite graph into an undirected graph that contains only top vertices.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

fromDataSet

public static <KT,KB,VVT,VVB,EV> BipartiteGraph<KT,KB,VVT,VVB,EV> fromDataSet(DataSet<Vertex<KT,VVT>> topVertices,
                                                                              DataSet<Vertex<KB,VVB>> bottomVertices,
                                                                              DataSet<BipartiteEdge<KT,KB,EV>> edges,
                                                                              ExecutionEnvironment context)

Create bipartite graph from datasets.

Parameters:

topVertices - dataset of top vertices in the graph

bottomVertices - dataset of bottom vertices in the graph

edges - dataset of edges between vertices

context - Flink execution context

Returns:

new bipartite graph created from provided datasets

getTopVertices

public DataSet<Vertex<KT,VVT>> getTopVertices()

Get dataset with top vertices.

Returns:

dataset with top vertices

getBottomVertices

public DataSet<Vertex<KB,VVB>> getBottomVertices()

Get dataset with bottom vertices.

Returns:

dataset with bottom vertices

getEdges

public DataSet<BipartiteEdge<KT,KB,EV>> getEdges()

Get dataset with graph edges.

Returns:

dataset with graph edges

projectionTopSimple

public Graph<KT,VVT,Tuple2<EV,EV>> projectionTopSimple()

Convert a bipartite graph into an undirected graph that contains only top vertices. An edge between two vertices in the new graph will exist only if the original bipartite graph contains a bottom vertex they are both connected to.

The simple projection performs a single join and returns edges containing the bipartite edge values.

Note: KT must override .equals(). This requirement may be removed in a future release.

Returns:

simple top projection of the bipartite graph

projectionBottomSimple

public Graph<KB,VVB,Tuple2<EV,EV>> projectionBottomSimple()

Convert a bipartite graph into an undirected graph that contains only bottom vertices. An edge between two vertices in the new graph will exist only if the original bipartite graph contains a top vertex they are both connected to.

The simple projection performs a single join and returns edges containing the bipartite edge values.

Note: KB must override .equals(). This requirement may be removed in a future release.

Returns:

simple bottom projection of the bipartite graph

projectionTopFull

public Graph<KT,VVT,Projection<KB,VVB,VVT,EV>> projectionTopFull()

Convert a bipartite graph into a graph that contains only top vertices. An edge between two vertices in the new graph will exist only if the original bipartite graph contains at least one bottom vertex they both connect to.

The full projection performs three joins and returns edges containing the connecting vertex ID and value, both top vertex values, and both bipartite edge values.

Note: KT must override .equals(). This requirement may be removed in a future release.

Returns:

full top projection of the bipartite graph

projectionBottomFull

public Graph<KB,VVB,Projection<KT,VVT,VVB,EV>> projectionBottomFull()

Convert a bipartite graph into a graph that contains only bottom vertices. An edge between two vertices in the new graph will exist only if the original bipartite graph contains at least one top vertex they both connect to.

The full projection performs three joins and returns edges containing the connecting vertex ID and value, both bottom vertex values, and both bipartite edge values.

Note: KB must override .equals(). This requirement may be removed in a future release.

Returns:

full bottom projection of the bipartite graph