@Override
public double centrality(WeightedGraph<Integer> weightedGraph, Integer node) {
ArrayList<Integer> allNodesButThis = new ArrayList<>(weightedGraph.allNodes());
allNodesButThis.remove(node);
List<PathBetweenNodes<Integer>> allShortestPaths =
weightedGraph
.allNodes()
.stream()
.flatMap(
n1 ->
weightedGraph
.allNodes()
.stream()
.filter(n2 -> n1 != n2)
.map(n2 -> weightedGraph.shortestPath(n1, n2)))
.filter(path -> path.isPresent())
.map(path -> path.get())
.collect(Collectors.toList());
double pathsWithNode =
allShortestPaths.stream().filter((path) -> (path.getNodes().contains(node))).count();
double centrality = pathsWithNode / allShortestPaths.size();
return centrality;
}
/**
* Devuelve el grado con el que el grupo indicado es un clique.
*
* @param datasetLoader
* @param group Grupo a comprobar.
* @return Valor difuso con el que un grupo es un clique.
*/
@Override
public double getMeasure(DatasetLoader<? extends Rating> datasetLoader, GroupOfUsers group)
throws CannotLoadRatingsDataset {
WeightedGraph<Integer> trustNetwork =
getWeightedGraphCalculation().computeTrustValues(datasetLoader, group.getIdMembers());
double sumDistance = 0;
for (int idMember1 : group.getIdMembers()) {
for (int idMember2 : group.getIdMembers()) {
double distance;
distance = trustNetwork.distance(idMember1, idMember2);
sumDistance += distance;
}
}
return sumDistance;
}
