/**
* Creates a new graph with the specified number of vertices that are connected with constant
* probability.
*
* @param numVertices the number of vertices.
* @param p the edge probability
* @param randomSeed a random seed
* @return a new random graph.
*/
public G generate(int numVertices, double p, long randomSeed) {
G g = builder.createGraph();
for (int i = 0; i < numVertices; i++) builder.addVertex(g);
return generate(g, p, randomSeed);
}
public G generate(int N, int k, double p) {
G graph = ringLatticeGenerator.generate(N, k);
Set<Edge> edges = new HashSet<Edge>();
for (Edge edge : graph.getEdges()) {
if (random.nextDouble() < p) {
edges.add(edge);
}
}
List<V> vertices = new ArrayList<V>(graph.getVertices().size());
vertices.addAll((Collection<? extends V>) graph.getVertices());
int doubleEdges = 0;
for (Edge edge : edges) {
V source;
if (random.nextBoolean()) {
source = (V) edge.getVertices().getFirst();
} else {
source = (V) edge.getVertices().getSecond();
}
builder.removeEdge(graph, (E) edge);
V target = null;
while (target == null) {
target = vertices.get(random.nextInt(vertices.size()));
if (source == target) target = null;
}
if (builder.addEdge(graph, source, target) == null) doubleEdges++;
}
logger.debug(String.format("Rejected %1$s double edges.", doubleEdges));
return graph;
}
@SuppressWarnings("unchecked")
private G enumerate(G graph, double p, long randomSeed) {
LinkedList<V> pending = new LinkedList<V>();
pending.addAll((Collection<? extends V>) graph.getVertices());
Random random = new Random(randomSeed);
V v1;
while ((v1 = pending.poll()) != null) {
for (V v2 : pending) {
if (random.nextDouble() <= p) {
builder.addEdge(graph, v1, v2);
}
}
}
return graph;
}
@SuppressWarnings("unchecked")
private G randomDraw(G graph, double p, long randomSeed) {
long n = graph.getVertices().size();
long M = n * (n - 1) / 2;
int m = (int) (p * M);
Random random = new Random(randomSeed);
List<V> vertices = new ArrayList<V>((Collection<? extends V>) graph.getVertices());
ProgressLogger.init(m, 1, 5);
for (int i = 0; i < m; i++) {
E edge = null;
while (edge == null) {
V vi = vertices.get(random.nextInt((int) n));
V vj = vertices.get(random.nextInt((int) n));
edge = builder.addEdge(graph, vi, vj);
}
ProgressLogger.step();
// if(i % 10000 == 0)
// logger.info(String.format("Created %1$s of %2$s edges.", i+1, m));
}
ProgressLogger.termiante();
return graph;
}