org.graphstream.algorithm

Interface DynamicAlgorithm

All Superinterfaces:

Algorithm

All Known Implementing Classes:

ChartConnectivityMeasure, ChartConnectivityMeasure.ChartEdgeConnectivityMeasure, ChartConnectivityMeasure.ChartVertexConnectivityMeasure, CommunityDistribution, CommunityMeasure, CommunityRelativeMeasure, ConnectedComponents, ConnectivityMeasure.EdgeConnectivityMeasure, ConnectivityMeasure.VertexConnectivityMeasure, DecentralizedCommunityAlgorithm, DegreeMeasure, DStar, DynamicOneToAllShortestPath, ElementCountMeasure, ElementCountMeasure.EdgeCountMeasure, ElementCountMeasure.NodeCountMeasure, EpidemicCommunityAlgorithm, Leung, Modularity, NetworkSimplex, NormalizedMutualInformation, PageRank, RandomWalk, SyncEpidemicCommunityAlgorithm, VariationOfInformation

public interface DynamicAlgorithm
extends Algorithm

Defines algorithms able to handle dynamics of a graph. This is an extension of the Algorithm so dynamic algorithms are composed of an initialization step followed by several computation steps. A last step, specific to dynamic algorithms, marks the termination of the algorithm and has to be used to close the computation. The following example computes the amount of apparitions of each node and the average value of apparitions for nodes :

 public class ApparitionAlgorithm extends SinkAdapter implements
                DynamicAlgorithm {
 
        Graph theGraph;
        HashMap<String, Integer> apparitions;
        double avg;
 
        public void init(Graph graph) {
                theGraph = graph;
                avg = 0;
                graph.addSink(this);
        }
 
        public void compute() {
                avg = 0;
 
                for (int a : apparitions.values())
                        avg += a;
 
                avg /= apparitions.size();
        }
 
        public void terminate() {
                graph.removeSink(this);
        }
 
        public double getAverageApparitions() {
                return avg;
        }
 
        public int getApparitions(String nodeId) {
                return apparitions.get(nodeId);
        }
 
        public void nodeAdded(String sourceId, long timeId, String nodeId) {
                int a = 0;
 
                if (apparitions.containsKey(nodeId))
                        a = apparitions.get(nodeId);
 
                apparitions.put(nodeId, a + 1);
        }
 
        public void stepBegins(String sourceId, long timeId, double step) {
                compute();
        }
 }
 

Note that in the example, the #terminate() method is used to remove the link between graph and the algorithm. The computation here is done at every step but can be done anywhere else, according to the algorithm requirements.

Method Summary

Modifier and Type	Method and Description
void	terminate() Terminate the dynamic algorithm.

Methods inherited from interface org.graphstream.algorithm.Algorithm

compute, init

Method Detail

terminate

void terminate()

Terminate the dynamic algorithm.

See Also:

Algorithm.init(org.graphstream.graph.Graph)