Exemple #1
0
void print_graph(Graph & G, NodeArray<int> & ind)
{
  int n = G.numberOfNodes();
  int m = G.numberOfEdges();
  printf("%d %d", n, m);

  Array<edge> list(m);

  ind.init(G, 0);
  node u;
  int a = 0;
  forall_nodes(u, G)
    ind[u] = a++;

  int i = 0;
  edge e;
  forall_edges(e, G)
    list[i++] = e;

  EdgeCmp cmp;
  list.quicksort(cmp);

  for (i=0; i<m; i++)
    print_ord(ind[list[i]->source()], ind[list[i]->target()]);
  printf("\n");
}
Exemple #2
0
/**
 * Copy the solution (Graph, Tour, Edges, and Headings) into those given.
 * @note Existing nodes and edges are cleared.
 */
void DubinsPathPlanner::copySolution(ogdf::Graph &G, ogdf::GraphAttributes &GA,
        ogdf::List<ogdf::node> &Tour, ogdf::List<ogdf::edge> &Edges,
        NodeArray<double> &Headings, double &cost) {
    DPP_ASSERT(m_haveSolution);

    // Copy the graph and attributes
    NodeArray<node> nodeCopyTable(m_G);
    EdgeArray<edge> edgeCopyTable(m_G);
    int n = copyGraph(m_G, m_GA, G, GA, nodeCopyTable, edgeCopyTable);

    // Copy the tour
    ogdf::ListIterator<ogdf::node> tourIter;
    for ( tourIter = m_Tour.begin(); tourIter != m_Tour.end(); tourIter++ ) {
        node u = *tourIter;
        node ucopy = nodeCopyTable(u);
        Tour.pushBack(ucopy);
    }

    // Copy the edge list
    ogdf::ListIterator<ogdf::edge> edgeIter;
    for ( edgeIter = m_Edges.begin(); edgeIter != m_Edges.end(); edgeIter++ ) {
        edge e = *edgeIter;
        edge ecopy = edgeCopyTable(e);
        Edges.pushBack(ecopy);
    }

    // Copy the headings
    Headings.init(G);
    node u;
    forall_nodes(u,m_G) {
        node ucopy = nodeCopyTable(u);
        Headings(ucopy) = m_Headings(u);
    }
Exemple #3
0
void StressMinimization::minimizeStress(
	GraphAttributes& GA,
	NodeArray<NodeArray<double> >& shortestPathMatrix,
	NodeArray<NodeArray<double> >& weightMatrix)
{
	const Graph& G = GA.constGraph();
	int numberOfPerformedIterations = 0;

	double prevStress = numeric_limits<double>::max();
	double curStress = numeric_limits<double>::max();

	if (m_terminationCriterion == STRESS) {
		curStress = calcStress(GA, shortestPathMatrix, weightMatrix);
	}

	NodeArray<double> newX;
	NodeArray<double> newY;
	NodeArray<double> newZ;

	if (m_terminationCriterion == POSITION_DIFFERENCE) {
		newX.init(G);
		newY.init(G);
		if (GA.has(GraphAttributes::threeD))
			newZ.init(G);
	}
	do {
		if (m_terminationCriterion == POSITION_DIFFERENCE) {
			if (GA.has(GraphAttributes::threeD))
				copyLayout(GA, newX, newY, newZ);
			else copyLayout(GA, newX, newY);
		}
		nextIteration(GA, shortestPathMatrix, weightMatrix);
		if (m_terminationCriterion == STRESS) {
			prevStress = curStress;
			curStress = calcStress(GA, shortestPathMatrix, weightMatrix);
		}
	} while (!finished(GA, ++numberOfPerformedIterations, newX, newY, prevStress, curStress));

	Logger::slout() << "Iteration count:\t" << numberOfPerformedIterations
		<< "\tStress:\t" << calcStress(GA, shortestPathMatrix, weightMatrix) << endl;
}
Exemple #4
0
void Graph::copy(const Graph &G, NodeArray<node> &mapNode,
	EdgeArray<edge> &mapEdge)
{
	if (G.m_nNodes == 0) return;

	mapNode.init(G,0);

	node vG;
	forall_nodes(vG,G) {
		node v = mapNode[vG] = pureNewNode();
		v->m_indeg = vG->m_indeg;
		v->m_outdeg = vG->m_outdeg;
	}
Exemple #5
0
void OptimalRanking::doCall(
	const Graph& G,
	NodeArray<int> &rank,
	EdgeArray<bool> &reversed,
	const EdgeArray<int> &length,
	const EdgeArray<int> &costOrig)
{
	MinCostFlowReinelt<int> mcf;

	// construct min-cost flow problem
	GraphCopy GC;
	GC.createEmpty(G);

	// compute connected component of G
	NodeArray<int> component(G);
	int numCC = connectedComponents(G,component);

	// intialize the array of lists of nodes contained in a CC
	Array<List<node> > nodesInCC(numCC);

	for(node v : G.nodes)
		nodesInCC[component[v]].pushBack(v);

	EdgeArray<edge> auxCopy(G);
	rank.init(G);

	for(int i = 0; i < numCC; ++i)
	{
		GC.initByNodes(nodesInCC[i], auxCopy);
		makeLoopFree(GC);

		for(edge e : GC.edges)
			if(reversed[GC.original(e)])
				GC.reverseEdge(e);

		// special cases:
		if(GC.numberOfNodes() == 1) {
			rank[GC.original(GC.firstNode())] = 0;
			continue;
		} else if(GC.numberOfEdges() == 1) {
			edge e = GC.original(GC.firstEdge());
			rank[e->source()] = 0;
			rank[e->target()] = length[e];
			continue;
		}

		EdgeArray<int> lowerBound(GC,0);
		EdgeArray<int> upperBound(GC,mcf.infinity());
		EdgeArray<int> cost(GC);
		NodeArray<int> supply(GC);

		for(edge e : GC.edges)
			cost[e] = -length[GC.original(e)];

		for(node v : GC.nodes) {
			int s = 0;
			edge e;
			forall_adj_edges(e,v) {
				if(v == e->source())
					s += costOrig[GC.original(e)];
				else
					s -= costOrig[GC.original(e)];
			}
			supply[v] = s;
		}

		OGDF_ASSERT(isAcyclic(GC) == true);

		// find min-cost flow
		EdgeArray<int> flow(GC);
		NodeArray<int> dual(GC);
#ifdef OGDF_DEBUG
		bool feasible =
#endif
			mcf.call(GC, lowerBound, upperBound, cost, supply, flow, dual);
		OGDF_ASSERT(feasible);

		for(node v : GC.nodes)
			rank[GC.original(v)] = dual[v];
	}
}
void VerticalEdgeLengthCompacter::computeTransitiveHull(const Graph& g, NodeArray<NodeArray<bool> >& transitiveHull){
	transitiveHull.init(g);
	node n;
	forall_nodes(n, g){
		transitiveHull[n].init(g, false);
	}
Exemple #7
0
T randomOptimalSteiner(
  int n,
  EdgeWeightedGraph<T> &graph,
  List<node> &terminals,
  NodeArray<bool> &isTerminal,
  EdgeWeightedGraphCopy<T> &tree
)
{
	OGDF_ASSERT(n >= 0);

	T result = 0;

	graph.clear();
	terminals.clear();
	tree.clear();
	tree.createEmpty(graph);
	isTerminal.init(graph, false);

	if(n > 0) {
		node source = graph.newNode();
		tree.newNode(source);
		isTerminal[source] = true;
		terminals.pushFront(source);

		if(n > 1) {
			int numberOfAdditionalNodes = randomNumber(0, n-2);
			int numberOfNodes = n - numberOfAdditionalNodes;
			int numberOfEdges = randomNumber(numberOfNodes-1 + numberOfAdditionalNodes*2, (n*(n-1))/2);

			for(int i = 1; i < numberOfNodes; i++) {
				node v = graph.chooseNode();
				node u = graph.newNode();
				tree.newNode(u);

				edge e = graph.newEdge(v, u, 1);
				result++;
				tree.newEdge(e, 1);
				if(isTerminal[v] && v != source) {
					isTerminal[v] = false;
					terminals.del(terminals.search(v));
				}

				isTerminal[u] = true;
				terminals.pushFront(u);
			}

			for(int i = numberOfNodes-1; i < numberOfEdges;) {
				node v = graph.chooseNode();
				node u = graph.chooseNode();
				while(u == v) { u = graph.chooseNode(); }

				if(numberOfAdditionalNodes > 0) {
					node w = graph.newNode();
					graph.newEdge(v, w, n);
					graph.newEdge(w, u, n);
					numberOfAdditionalNodes--;
					i += 2;
				}
				else {
					if(graph.searchEdge(v, u) == NULL && graph.searchEdge(u, v) == NULL) {
						graph.newEdge(v, u, n);
						i++;
					}
				}
			}
			OGDF_ASSERT(graph.numberOfEdges() == numberOfEdges);
			OGDF_ASSERT(tree.numberOfNodes() == numberOfNodes);
			OGDF_ASSERT(tree.numberOfEdges() == numberOfNodes - 1);
		}
	}
	OGDF_ASSERT(graph.numberOfNodes() == n);
	OGDF_ASSERT(isSimpleUndirected(graph));
	OGDF_ASSERT(isConnected(graph));
	return result;
}
Exemple #8
0
void BasicPageRank::call(
	const Graph& graph,
	const EdgeArray<double>& edgeWeight,
	NodeArray<double>& pageRankResult)
{
	const double initialPageRank = 1.0 / (double)graph.numberOfNodes();
	const double maxPageRankDeltaBound = initialPageRank * m_threshold;

	// the two ping pong buffer
	NodeArray<double> pageRankPing(graph, 0.0);
	NodeArray<double> pageRankPong(graph, 0.0);

	NodeArray<double>* pCurrPageRank = &pageRankPing;
	NodeArray<double>* pNextPageRank = &pageRankPong;

	NodeArray<double> nodeNorm(graph);

	for (node v = graph.firstNode(); v; v = v->succ())
	{
		double sum = 0.0;
		for (adjEntry adj = v->firstAdj(); adj; adj = adj->succ())
		{
			edge e = adj->theEdge();
			sum += edgeWeight[e];
		}
		nodeNorm[v] = 1.0 / sum;
	}

	pCurrPageRank->init(graph, initialPageRank);

	// main iteration loop
	int numIterations = 0;
	bool converged = false;
	// check conditions
	while ( !converged && (numIterations < m_maxNumIterations) )
	{
		// init the result of this iteration
		pNextPageRank->init(graph, (1.0 - m_dampingFactor) / (double)graph.numberOfNodes());
		// calculate the transfer between each node
		for (edge e = graph.firstEdge(); e; e = e->succ())
		{
			node v = e->source();
			node w = e->target();

			double vwTransfer = (edgeWeight[e] * nodeNorm[v] * (*pCurrPageRank)[v]);
			double wvTransfer = (edgeWeight[e] * nodeNorm[w] * (*pCurrPageRank)[w]);
			(*pNextPageRank)[w] += vwTransfer;
			(*pNextPageRank)[v] += wvTransfer;
		}

		// damping and calculating change
		double maxPageRankDelta = 0.0;
		for (node v = graph.firstNode(); v; v = v->succ())
		{
			(*pNextPageRank)[v] *= m_dampingFactor;
			double pageRankDelta = fabs((*pNextPageRank)[v] - (*pCurrPageRank)[v]);
			maxPageRankDelta = std::max(maxPageRankDelta, pageRankDelta);
		}

		// swap ping and pong, pong ping, ping pong, lalalala
		std::swap(pNextPageRank, pCurrPageRank);
		numIterations++;

		// check if the change is small enough
		converged = (maxPageRankDelta < maxPageRankDeltaBound);
	}

	// normalization
	double maxPageRank = (*pCurrPageRank)[graph.firstNode()];
	double minPageRank = (*pCurrPageRank)[graph.firstNode()];
	for (node v = graph.firstNode(); v; v = v->succ())
	{
		maxPageRank = std::max(maxPageRank, (*pCurrPageRank)[v]);
		minPageRank = std::min(minPageRank, (*pCurrPageRank)[v]);
	}

	// init result
	pageRankResult.init(graph);
	for (node v = graph.firstNode(); v; v = v->succ())
	{
		double r = ((*pCurrPageRank)[v] - minPageRank) / (maxPageRank - minPageRank);
		pageRankResult[v] = r;
	}
	// result is now between 0 and 1
}