edu.uci.ics.jung.graph.filters
Interface Filter

All Known Subinterfaces:

EfficientFilter, LevelFilter

All Known Implementing Classes:

AlphabeticVertexFilter, GeneralEdgeAcceptFilter, GeneralVertexAcceptFilter, KNeighborhoodFilter, SerialFilter, TrivialFilter, WeightedEdgeGraphFilter

public interface Filter

A Filter returns a subgraph of a Graph, in the form of an UnsassembledGraph. That UnsassembledGraph can then be turned into a Graph with a call to assemble(). A Filter, then, selects the subset of vertices and edges and from them creates an UnassembledGraph (presumably, with one of its two constructors.)

An UnsassembledGraph represents all the vertices (and at least all the edges) of a Graph that pass the subset. However, they have not been "assembled" into something that fulfills the Graph contract. (In particular, the Vertices and Edges that make up the UnassembledGraph still report, through getGraph(), that they are members of the original, and they still are connected to all the original edges.

After the call to assemble, the new Graph is valid , following the Graph contract fully.

Sample code

This code is taken from the JUnit tests for the filter code, with minor modifications. It demonstrates how to walk through the filter process.

 Graph g = TestGraphs.createTestGraph( true );                   
 // creates a graph.
 EdgeWeightLabeller ewl = EdgeWeightLabeller.getLabeller( g );
 // links each edge to a weight.
 WeightedEdgeGraphFilter wgf = new WeightedEdgeGraphFilter( 0, ewl );
 // creates a filter based on this weight

 wgf.setValue(3);
 // sets the threshold at 3.
 // at this point, the Filter is ready to block any edges with a weight less than 3.

 UnassembledGraph ug = wgf.filter(g);
 // this UnassembledGraph contains all edges of weight greater than three, and all vertices in g
 
 Graph sub_g = ug.assemble();
 

At the end of this code, the new graph sub_g contains a copy of some edges, and all nodes, of g. From here, we can treat it as a Graph. Note that calls like getEquivalentVertex( Graph ) will do the right thing on the vertices of sub_g and point back to g.

In addition, we now have access to the GraphAssemblyRecord that corresponds to the graph.

 	GraphAssemblyRecord gar = getAssemblyRecord( sub_g );
  String filterName = gar.getName();
 

Author:

danyelf

See Also:

EfficientFilter

Method Summary

UnassembledGraph	filter(Graph g) Filters a graph by returning an UnassembledGraph consisting of nodes and edges that pass the filter.
java.lang.String	getName() Gets a name that describes this filter.

Method Detail

filter

public UnassembledGraph filter(Graph g)

Filters a graph by returning an UnassembledGraph consisting of nodes and edges that pass the filter.

Parameters:

g - An input graph to be filtered.

Returns:

an UnassembledGraph that contains the subset of vertices and edges from g pass the filter.

getName

public java.lang.String getName()

Gets a name that describes this filter. It is used by the auditing methods in GraphAssemblyRecord

Returns:

A string that describes the filter.