Example #1
0
/*
 * Just a helper method to avoid ugly code in Parser#readEdges method. It just
 * populates \a nodes list with either a given \a v node (if not nullptr) or all
 * nodes in certain cluster found by performing a lookup with given \a id in
 * \a clusterId association.
 */
static inline bool edgeNodes(
	node v,
	const std::string &id,
	const HashArray<std::string, cluster> &clusterId,
	List<node> &nodes)
{
	if(v) {
		nodes.clear();
		nodes.pushBack(v);
	} else {
		const cluster c = clusterId[id];
		if(!c) {
			return false;
		}

		c->getClusterNodes(nodes);
	}

	return true;
}
Example #2
0
//todo: is called only once, but could be sped up the same way as the co-conn check
void MaxCPlanarMaster::clusterConnection(cluster c, GraphCopy &gc, double &upperBoundC) {
	// For better performance, a node array is used to indicate which nodes are contained
	// in the currently considered cluster.
	NodeArray<bool> vInC(gc,false);
	// First check, if the current cluster \a c is a leaf cluster.
	// If so, compute the number of edges that have at least to be added
	// to make the cluster induced graph connected.
	if (c->cCount()==0) { 	//cluster \a c is a leaf cluster
		GraphCopy *inducedC = new GraphCopy((const Graph&)gc);
		List<node> clusterNodes;
		c->getClusterNodes(clusterNodes); // \a clusterNodes now contains all (original) nodes of cluster \a c.
		for (node w : clusterNodes) {
			vInC[gc.copy(w)] = true;
		}

		// Delete all nodes from \a inducedC that do not belong to the cluster,
		// in order to obtain the cluster induced graph.
		node v = inducedC->firstNode();
		while (v!=nullptr)  {
			node w = v->succ();
			if (!vInC[inducedC->original(v)]) inducedC->delNode(v);
			v = w;
		}

		// Determine number of connected components of cluster induced graph.
		//Todo: check could be skipped
		if (!isConnected(*inducedC)) {

			NodeArray<int> conC(*inducedC);
			int nCC = connectedComponents(*inducedC,conC);
			//at least #connected components - 1 edges have to be added.
			upperBoundC -= (nCC-1)*m_largestConnectionCoeff;
		}
		delete inducedC;
	// Cluster \a c is an "inner" cluster. Process all child clusters first.
	} else {	//c->cCount is != 0, process all child clusters first

		for (cluster ci : c->children) {
			clusterConnection(ci, gc, upperBoundC);
		}

		// Create cluster induced graph.
		GraphCopy *inducedC = new GraphCopy((const Graph&)gc);
		List<node> clusterNodes;
		c->getClusterNodes(clusterNodes); //\a clusterNodes now contains all (original) nodes of cluster \a c.
		for (node w : clusterNodes) {
			vInC[gc.copy(w)] = true;
		}
		node v = inducedC->firstNode();
		while (v!=nullptr)  {
			node w = v->succ();
			if (!vInC[inducedC->original(v)]) inducedC->delNode(v);
			v = w;
		}

		// Now collapse each child cluster to one node and determine #connected components of \a inducedC.
		List<node> oChildClusterNodes;
		List<node> cChildClusterNodes;
		for (cluster ci : c->children) {
			ci->getClusterNodes(oChildClusterNodes);
			// Compute corresponding nodes of graph \a inducedC.
			for (node u : oChildClusterNodes) {
				node copy = inducedC->copy(gc.copy(u));
				cChildClusterNodes.pushBack(copy);
			}
			inducedC->collapse(cChildClusterNodes);
			oChildClusterNodes.clear();
			cChildClusterNodes.clear();
		}
		// Now, check \a inducedC for connectivity.
		if (!isConnected(*inducedC)) {

			NodeArray<int> conC(*inducedC);
			int nCC = connectedComponents(*inducedC,conC);
			//at least #connected components - 1 edges have to added.
			upperBoundC -= (nCC-1)*m_largestConnectionCoeff;
		}
		delete inducedC;
	}
}//clusterConnection