private Graph condense(Graph mimStructure, Graph mimbuildStructure) {
// System.out.println("Uncondensed: " + mimbuildStructure);
Map<Node, Node> substitutions = new HashMap<Node, Node>();
for (Node node : mimbuildStructure.getNodes()) {
for (Node _node : mimStructure.getNodes()) {
if (node.getName().startsWith(_node.getName())) {
substitutions.put(node, _node);
break;
}
substitutions.put(node, node);
}
}
HashSet<Node> nodes = new HashSet<Node>(substitutions.values());
Graph graph = new EdgeListGraph(new ArrayList<Node>(nodes));
for (Edge edge : mimbuildStructure.getEdges()) {
Node node1 = substitutions.get(edge.getNode1());
Node node2 = substitutions.get(edge.getNode2());
if (node1 == node2) continue;
if (graph.isAdjacentTo(node1, node2)) continue;
graph.addEdge(new Edge(node1, node2, edge.getEndpoint1(), edge.getEndpoint2()));
}
// System.out.println("Condensed: " + graph);
return graph;
}
public Graph orient() {
Graph skeleton = GraphUtils.undirectedGraph(getPattern());
Graph graph = new EdgeListGraph(skeleton.getNodes());
List<Node> nodes = skeleton.getNodes();
// Collections.shuffle(nodes);
if (isR1Done()) {
ruleR1(skeleton, graph, nodes);
}
for (Edge edge : skeleton.getEdges()) {
if (!graph.isAdjacentTo(edge.getNode1(), edge.getNode2())) {
graph.addUndirectedEdge(edge.getNode1(), edge.getNode2());
}
}
if (isR2Done()) {
ruleR2(skeleton, graph);
}
if (isMeekDone()) {
new MeekRules().orientImplied(graph);
}
return graph;
}
// Cannot be done if the graph changes.
public void setInitialGraph(Graph initialGraph) {
initialGraph = GraphUtils.replaceNodes(initialGraph, variables);
out.println("Initial graph variables: " + initialGraph.getNodes());
out.println("Data set variables: " + variables);
if (!new HashSet<Node>(initialGraph.getNodes()).equals(new HashSet<Node>(variables))) {
throw new IllegalArgumentException("Variables aren't the same.");
}
this.initialGraph = initialGraph;
}
////////////////////////////////////////////////
// collect in rTupleList all unshielded tuples
////////////////////////////////////////////////
private List<Node[]> getRTuples() {
List<Node[]> rTuples = new ArrayList<Node[]>();
List<Node> nodes = graph.getNodes();
for (Node j : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(j);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node i = adjacentNodes.get(combination[0]);
Node k = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (!graph.isAdjacentTo(i, k)) {
Node[] newTuple = {i, j, k};
rTuples.add(newTuple);
}
}
}
return (rTuples);
}
public List<Triple> getUnshieldedCollidersFromGraph(Graph graph) {
List<Triple> colliders = new ArrayList<>();
List<Node> nodes = graph.getNodes();
for (Node b : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(b);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node a = adjacentNodes.get(combination[0]);
Node c = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (graph.isAdjacentTo(a, c)) {
continue;
}
if (graph.isDefCollider(a, b, c)) {
colliders.add(new Triple(a, b, c));
}
}
}
return colliders;
}
/**
* Double checks a sepset map against a pattern to make sure that X is adjacent to Y in the
* pattern iff {X, Y} is not in the domain of the sepset map.
*
* @param sepset a sepset map, over variables V.
* @param pattern a pattern over variables W, V subset of W.
* @return true if the sepset map is consistent with the pattern.
*/
public static boolean verifySepsetIntegrity(SepsetMap sepset, Graph pattern) {
for (Node x : pattern.getNodes()) {
for (Node y : pattern.getNodes()) {
if (x == y) {
continue;
}
if ((pattern.isAdjacentTo(y, x)) != (sepset.get(x, y) == null)) {
System.out.println("Sepset not consistent with graph for {" + x + ", " + y + "}");
return false;
}
}
}
return true;
}
public TimeLagGraphWrapper(GraphWrapper graphWrapper) {
if (graphWrapper == null) {
throw new NullPointerException("No graph wrapper.");
}
TimeLagGraph graph = new TimeLagGraph();
Graph _graph = graphWrapper.getGraph();
for (Node node : _graph.getNodes()) {
Node _node = node.like(node.getName() + ":0");
_node.setNodeType(node.getNodeType());
graph.addNode(_node);
}
for (Edge edge : _graph.getEdges()) {
if (!Edges.isDirectedEdge(edge)) {
throw new IllegalArgumentException();
}
Node from = edge.getNode1();
Node to = edge.getNode2();
Node _from = graph.getNode(from.getName(), 1);
Node _to = graph.getNode(to.getName(), 0);
graph.addDirectedEdge(_from, _to);
}
this.graph = graph;
}
// ===========================SCORING METHODS===================//
public double scoreDag(Graph graph) {
Graph dag = new EdgeListGraphSingleConnections(graph);
buildIndexing(graph);
double score = 0.0;
for (Node y : dag.getNodes()) {
Set<Node> parents = new HashSet<Node>(dag.getParents(y));
int nextIndex = -1;
for (int i = 0; i < getVariables().size(); i++) {
nextIndex = hashIndices.get(variables.get(i));
}
int parentIndices[] = new int[parents.size()];
Iterator<Node> pi = parents.iterator();
int count = 0;
while (pi.hasNext()) {
Node nextParent = pi.next();
parentIndices[count++] = hashIndices.get(nextParent);
}
if (this.isDiscrete()) {
score += localDiscreteScore(nextIndex, parentIndices);
} else {
score += localSemScore(nextIndex, parentIndices);
}
}
return score;
}
private Graph changeLatentNames(Graph full, Clusters measurements, List<String> latentVarList) {
Graph g2 = null;
try {
g2 = (Graph) new MarshalledObject(full).get();
} catch (IOException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
for (int i = 0; i < measurements.getNumClusters(); i++) {
List<String> d = measurements.getCluster(i);
String latentName = latentVarList.get(i);
for (Node node : full.getNodes()) {
if (!(node.getNodeType() == NodeType.LATENT)) {
continue;
}
List<Node> _children = full.getChildren(node);
_children.removeAll(ReidentifyVariables.getLatents(full));
List<String> childNames = getNames(_children);
if (new HashSet<String>(childNames).equals(new HashSet<String>(d))) {
g2.getNode(node.getName()).setName(latentName);
}
}
}
return g2;
}
/**
* Constructs a new on-the-fly BayesIM that will calculate conditional probabilities on the fly
* from the given discrete data set, for the given Bayes PM.
*
* @param bayesPm the given Bayes PM, which specifies a directed acyclic graph for a Bayes net and
* parametrization for the Bayes net, but not actual values for the parameters.
* @param dataSet the discrete data set from which conditional probabilities should be estimated
* on the fly.
*/
public OnTheFlyMarginalCalculator(BayesPm bayesPm, DataSet dataSet)
throws IllegalArgumentException {
if (bayesPm == null) {
throw new NullPointerException();
}
if (dataSet == null) {
throw new NullPointerException();
}
// Make sure all of the variables in the PM are in the data set;
// otherwise, estimation is impossible.
BayesUtils.ensureVarsInData(bayesPm.getVariables(), dataSet);
// DataUtils.ensureVariablesExist(bayesPm, dataSet);
this.bayesPm = new BayesPm(bayesPm);
// Get the nodes from the BayesPm. This fixes the order of the nodes
// in the BayesIm, independently of any change to the BayesPm.
// (This order must be maintained.)
Graph graph = bayesPm.getDag();
this.nodes = graph.getNodes().toArray(new Node[0]);
// Initialize.
initialize();
// Create a subset of the data set with the variables of the IM, in
// the order of the IM.
List<Node> variables = getVariables();
this.dataSet = dataSet.subsetColumns(variables);
// Create a tautologous proposition for evidence.
this.evidence = new Evidence(Proposition.tautology(this));
}
/**
* Step C of PC; orients colliders using specified sepset. That is, orients x *-* y *-* z as x *->
* y <-* z just in case y is in Sepset({x, z}).
*/
public Map<Triple, Double> findCollidersUsingSepsets(
SepsetProducer sepsetProducer, Graph graph, boolean verbose, IKnowledge knowledge) {
TetradLogger.getInstance().log("details", "Starting Collider Orientation:");
Map<Triple, Double> colliders = new HashMap<>();
System.out.println("Looking for colliders");
List<Node> nodes = graph.getNodes();
for (Node b : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(b);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node a = adjacentNodes.get(combination[0]);
Node c = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (graph.isAdjacentTo(a, c)) {
continue;
}
List<Node> sepset = sepsetProducer.getSepset(a, c);
if (sepset == null) continue;
// if (sepsetProducer.getPValue() < 0.5) continue;
if (!sepset.contains(b)) {
if (verbose) {
// boolean dsep = this.dsep.isIndependent(a, c);
// System.out.println("QQQ p = " + independenceTest.getPValue() +
// " " + dsep);
System.out.println(
"\nCollider orientation <" + a + ", " + b + ", " + c + "> sepset = " + sepset);
}
colliders.put(new Triple(a, b, c), sepsetProducer.getPValue());
TetradLogger.getInstance()
.log("colliderOrientations", SearchLogUtils.colliderOrientedMsg(a, b, c, sepset));
}
}
}
TetradLogger.getInstance().log("details", "Finishing Collider Orientation.");
System.out.println("Done finding colliders");
return colliders;
}
/**
* Transforms a maximally directed pattern (PDAG) represented in graph <code>g</code> into an
* arbitrary DAG by modifying <code>g</code> itself. Based on the algorithm described in
* Chickering (2002) "Optimal structure identification with greedy search" Journal of Machine
* Learning Research. R. Silva, June 2004
*/
public static void pdagToDag(Graph g) {
Graph p = new EdgeListGraph(g);
List<Edge> undirectedEdges = new ArrayList<Edge>();
for (Edge edge : g.getEdges()) {
if (edge.getEndpoint1() == Endpoint.TAIL
&& edge.getEndpoint2() == Endpoint.TAIL
&& !undirectedEdges.contains(edge)) {
undirectedEdges.add(edge);
}
}
g.removeEdges(undirectedEdges);
List<Node> pNodes = p.getNodes();
do {
Node x = null;
for (Node pNode : pNodes) {
x = pNode;
if (p.getChildren(x).size() > 0) {
continue;
}
Set<Node> neighbors = new HashSet<Node>();
for (Edge edge : p.getEdges()) {
if (edge.getNode1() == x || edge.getNode2() == x) {
if (edge.getEndpoint1() == Endpoint.TAIL && edge.getEndpoint2() == Endpoint.TAIL) {
if (edge.getNode1() == x) {
neighbors.add(edge.getNode2());
} else {
neighbors.add(edge.getNode1());
}
}
}
}
if (neighbors.size() > 0) {
Collection<Node> parents = p.getParents(x);
Set<Node> all = new HashSet<Node>(neighbors);
all.addAll(parents);
if (!GraphUtils.isClique(all, p)) {
continue;
}
}
for (Node neighbor : neighbors) {
Node node1 = g.getNode(neighbor.getName());
Node node2 = g.getNode(x.getName());
g.addDirectedEdge(node1, node2);
}
p.removeNode(x);
break;
}
pNodes.remove(x);
} while (pNodes.size() > 0);
}
private List<String> measuredNames(Graph graph) {
List<String> names = new ArrayList<>();
for (Node node : graph.getNodes()) {
if (node.getNodeType() == NodeType.MEASURED) {
names.add(node.getName());
}
}
return names;
}
public static boolean meekR1Locally2(
Graph graph, Knowledge knowledge, IndependenceTest test, int depth) {
List<Node> nodes = graph.getNodes();
boolean changed = true;
while (changed) {
changed = false;
for (Node a : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(a);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node b = adjacentNodes.get(combination[0]);
Node c = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (graph.isAdjacentTo(b, c)) {
continue;
}
if (graph.getEndpoint(b, a) == Endpoint.ARROW && graph.isUndirectedFromTo(a, c)) {
if (existsLocalSepsetWithoutDet(b, a, c, test, graph, depth)) {
continue;
}
if (isArrowpointAllowed(a, c, knowledge)) {
graph.setEndpoint(a, c, Endpoint.ARROW);
TetradLogger.getInstance()
.edgeOriented(SearchLogUtils.edgeOrientedMsg("Meek R1", graph.getEdge(a, c)));
changed = true;
}
} else if (graph.getEndpoint(c, a) == Endpoint.ARROW && graph.isUndirectedFromTo(a, b)) {
if (existsLocalSepsetWithoutDet(b, a, c, test, graph, depth)) {
continue;
}
if (isArrowpointAllowed(a, b, knowledge)) {
graph.setEndpoint(a, b, Endpoint.ARROW);
TetradLogger.getInstance()
.edgeOriented(SearchLogUtils.edgeOrientedMsg("Meek R1", graph.getEdge(a, b)));
changed = true;
}
}
}
}
}
return changed;
}
/**
* Performs step C of the algorithm, as indicated on page xxx of CPS, with the modification that
* X--W--Y is oriented as X-->W<--Y if W is *determined by* the sepset of (X, Y), rather than W
* just being *in* the sepset of (X, Y).
*/
public static void pcdOrientC(
SepsetMap set, IndependenceTest test, Knowledge knowledge, Graph graph) {
TetradLogger.getInstance().log("info", "Staring Collider Orientation:");
List<Node> nodes = graph.getNodes();
for (Node y : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(y);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node x = adjacentNodes.get(combination[0]);
Node z = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (graph.isAdjacentTo(x, z)) {
continue;
}
List<Node> sepset = set.get(x, z);
if (sepset == null) {
continue;
}
List<Node> augmentedSet = new LinkedList<Node>(sepset);
augmentedSet.add(y);
if (test.determines(sepset, y)) {
continue;
}
//
if (!test.splitDetermines(sepset, x, z) && test.splitDetermines(augmentedSet, x, z)) {
continue;
}
if (!isArrowpointAllowed(x, y, knowledge) || !isArrowpointAllowed(z, y, knowledge)) {
continue;
}
graph.setEndpoint(x, y, Endpoint.ARROW);
graph.setEndpoint(z, y, Endpoint.ARROW);
TetradLogger.getInstance()
.log("colliderOriented", SearchLogUtils.colliderOrientedMsg(x, y, z));
}
}
TetradLogger.getInstance().log("info", "Finishing Collider Orientation.");
}
/**
* Provides methods for estimating a Bayes IM from an existing BayesIM and a discrete dataset
* using EM (Expectation Maximization). The data columns in the given data must be equal to a
* variable in the given Bayes IM but the latter may contain variables which don't occur in the
* dataset (latent variables). The first argument of the constructoris the BayesPm whose graph
* contains latent and observed variables. The second is the dataset of observed variables;
* missing value codes may be present.
*/
public EmBayesEstimator(BayesPm bayesPm, DataSet dataSet) {
if (bayesPm == null) {
throw new NullPointerException();
}
if (dataSet == null) {
throw new NullPointerException();
}
List<Node> observedVars = new ArrayList<Node>();
this.bayesPm = bayesPm;
this.dataSet = dataSet;
// this.variables = Collections.unmodifiableList(vars);
graph = bayesPm.getDag();
this.nodes = new Node[graph.getNumNodes()];
Iterator<Node> it = graph.getNodes().iterator();
for (int i = 0; i < this.nodes.length; i++) {
this.nodes[i] = it.next();
// System.out.println("node " + i + " " + nodes[i]);
}
for (int i = 0; i < this.nodes.length; i++) {
if (nodes[i].getNodeType() == NodeType.MEASURED) {
observedVars.add(bayesPm.getVariable(nodes[i]));
}
}
// Make sure variables in dataset are measured variables in the BayesPM
// for (Node dataSetVariable : this.dataSet.getVariables()) {
// if (!observedVars.contains(dataSetVariable)) {
// throw new IllegalArgumentException(
// "Some var in the dataset is not a " +
// "measured variable in the Bayes net");
// }
// }
// Make sure all measured variables in the BayesPm are in the discrete dataset
for (Node observedVar : observedVars) {
try {
this.dataSet.getVariable(observedVar.getName());
} catch (Exception e) {
throw new IllegalArgumentException(
"Some observed var in the Bayes net " + "is not in the dataset: " + observedVar);
}
}
findBayesNetObserved(); // Sets bayesPmObs
initialize();
}
private Graph structure(Graph mim) {
List<Node> latents = new ArrayList<Node>();
for (Node node : mim.getNodes()) {
if (node.getNodeType() == NodeType.LATENT) {
latents.add(node);
}
}
return mim.subgraph(latents);
}
private Graph restrictToEmpiricalLatents(Graph mimStructure, Graph mimbuildStructure) {
Graph _mim = new EdgeListGraph(mimStructure);
for (Node node : mimbuildStructure.getNodes()) {
if (!mimbuildStructure.containsNode(node)) {
_mim.removeNode(node);
}
}
return _mim;
}
/** Meek's rule R3. If a--b, a--c, a--d, c-->b, c-->b, then orient a-->b. */
public static boolean meekR3(Graph graph, Knowledge knowledge) {
List<Node> nodes = graph.getNodes();
boolean changed = false;
for (Node a : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(a);
if (adjacentNodes.size() < 3) {
continue;
}
for (Node b : adjacentNodes) {
List<Node> otherAdjacents = new LinkedList<Node>(adjacentNodes);
otherAdjacents.remove(b);
if (!graph.isUndirectedFromTo(a, b)) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(otherAdjacents.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node c = otherAdjacents.get(combination[0]);
Node d = otherAdjacents.get(combination[1]);
if (graph.isAdjacentTo(c, d)) {
continue;
}
if (!graph.isUndirectedFromTo(a, c)) {
continue;
}
if (!graph.isUndirectedFromTo(a, d)) {
continue;
}
if (graph.isDirectedFromTo(c, b) && graph.isDirectedFromTo(d, b)) {
if (isArrowpointAllowed(a, b, knowledge)) {
graph.setEndpoint(a, b, Endpoint.ARROW);
TetradLogger.getInstance()
.edgeOriented(SearchLogUtils.edgeOrientedMsg("Meek R3", graph.getEdge(a, b)));
changed = true;
break;
}
}
}
}
}
return changed;
}
public List<Node> findMb(String targetName) {
Node target = getVariableForName(targetName);
Pc search = new Pc(test);
search.setDepth(depth);
Graph graph = search.search();
MbUtils.trimToMbNodes(graph, target, false);
List<Node> mbVariables = graph.getNodes();
mbVariables.remove(target);
return mbVariables;
}
public static void arrangeByKnowledgeTiers(Graph graph, Knowledge knowledge) {
if (knowledge.getNumTiers() == 0) {
throw new IllegalArgumentException("There are no Tiers to arrange.");
}
List<Node> nodes = graph.getNodes();
List<String> varNames = new ArrayList<String>();
int ySpace = 500 / knowledge.getNumTiers();
ySpace = ySpace < 50 ? 50 : ySpace;
for (Node node1 : nodes) {
varNames.add(node1.getName());
}
List<String> notInTier = knowledge.getVarsNotInTier(varNames);
int x = 0;
int y = 50 - ySpace;
if (notInTier.size() > 0) {
y += ySpace;
for (String name : notInTier) {
x += 90;
Node node = graph.getNode(name);
if (node != null) {
node.setCenterX(x);
node.setCenterY(y);
}
}
}
for (int i = 0; i < knowledge.getNumTiers(); i++) {
List<String> tier = knowledge.getTier(i);
y += ySpace;
x = -25;
for (String name : tier) {
x += 90;
Node node = graph.getNode(name);
if (node != null) {
node.setCenterX(x);
node.setCenterY(y);
}
}
}
}
private static double characteristicPathLength(Graph g) {
List<Node> nodes = g.getNodes();
int total = 0;
int count = 0;
for (int i = 0; i < nodes.size(); i++) {
for (int j = i; j < nodes.size(); j++) {
int shortest = shortestPath(nodes.get(i), nodes.get(j), g);
total += shortest;
count++;
}
}
return total / (double) count;
}
public void testAlternativeGraphs() {
// UniformGraphGenerator gen = new UniformGraphGenerator(UniformGraphGenerator.ANY_DAG);
// gen.setNumNodes(100);
// gen.setMaxEdges(200);
// gen.setMaxDegree(30);
// gen.setMaxInDegree(30);
// gen.setMaxOutDegree(30);
//// gen.setNumIterations(3000000);
// gen.setResamplingDegree(10);
//
// gen.generate();
//
// Graph graph = gen.getDag();
Graph graph = weightedRandomGraph(250, 400);
List<Integer> degreeCounts = new ArrayList<Integer>();
Map<Integer, Integer> degreeCount = new HashMap<Integer, Integer>();
for (Node node : graph.getNodes()) {
int degree = graph.getNumEdges(node);
degreeCounts.add(degree);
if (degreeCount.get(degree) == null) {
degreeCount.put(degree, 0);
}
degreeCount.put(degree, degreeCount.get(degree) + 1);
}
Collections.sort(degreeCounts);
System.out.println(degreeCounts);
List<Integer> _degrees = new ArrayList<Integer>(degreeCount.keySet());
Collections.sort(_degrees);
for (int i : _degrees) {
int j = degreeCount.get(i);
// System.out.println(i + " " + j);
System.out.println(log(i + 1) + " " + log(j));
}
System.out.println("\nCPL = " + characteristicPathLength(graph));
Graph erGraph = erdosRenyiGraph(200, 200);
System.out.println("\n ER CPL = " + characteristicPathLength(erGraph));
}
/**
* Step C of PC; orients colliders using specified sepset. That is, orients x *-* y *-* z as x *->
* y <-* z just in case y is in Sepset({x, z}).
*/
public static void orientCollidersUsingSepsets(SepsetMap set, Knowledge knowledge, Graph graph) {
TetradLogger.getInstance().log("info", "Starting Collider Orientation:");
// verifySepsetIntegrity(set, graph);
List<Node> nodes = graph.getNodes();
for (Node a : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(a);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node b = adjacentNodes.get(combination[0]);
Node c = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (graph.isAdjacentTo(b, c)) {
continue;
}
List<Node> sepset = set.get(b, c);
if (sepset != null
&& !sepset.contains(a)
&& isArrowpointAllowed(b, a, knowledge)
&& isArrowpointAllowed(c, a, knowledge)) {
graph.setEndpoint(b, a, Endpoint.ARROW);
graph.setEndpoint(c, a, Endpoint.ARROW);
TetradLogger.getInstance()
.log("colliderOriented", SearchLogUtils.colliderOrientedMsg(b, a, c, sepset));
}
}
}
TetradLogger.getInstance().log("info", "Finishing Collider Orientation.");
}
/** If */
public static boolean meekR2(Graph graph, Knowledge knowledge) {
List<Node> nodes = graph.getNodes();
boolean changed = false;
for (Node a : nodes) {
List<Node> adjacentNodes = graph.getAdjacentNodes(a);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node b = adjacentNodes.get(combination[0]);
Node c = adjacentNodes.get(combination[1]);
if (graph.isDirectedFromTo(b, a)
&& graph.isDirectedFromTo(a, c)
&& graph.isUndirectedFromTo(b, c)) {
if (isArrowpointAllowed(b, c, knowledge)) {
graph.setEndpoint(b, c, Endpoint.ARROW);
TetradLogger.getInstance()
.edgeOriented(SearchLogUtils.edgeOrientedMsg("Meek R2", graph.getEdge(b, c)));
}
} else if (graph.isDirectedFromTo(c, a)
&& graph.isDirectedFromTo(a, b)
&& graph.isUndirectedFromTo(c, b)) {
if (isArrowpointAllowed(c, b, knowledge)) {
graph.setEndpoint(c, b, Endpoint.ARROW);
TetradLogger.getInstance()
.edgeOriented(SearchLogUtils.edgeOrientedMsg("Meek R2", graph.getEdge(c, b)));
}
}
}
}
return changed;
}
public static void orientCollidersLocally(
Knowledge knowledge, Graph graph, IndependenceTest test, int depth, Set<Node> nodesToVisit) {
TetradLogger.getInstance().log("info", "Starting Collider Orientation:");
if (nodesToVisit == null) {
nodesToVisit = new HashSet<Node>(graph.getNodes());
}
for (Node a : nodesToVisit) {
List<Node> adjacentNodes = graph.getAdjacentNodes(a);
if (adjacentNodes.size() < 2) {
continue;
}
ChoiceGenerator cg = new ChoiceGenerator(adjacentNodes.size(), 2);
int[] combination;
while ((combination = cg.next()) != null) {
Node b = adjacentNodes.get(combination[0]);
Node c = adjacentNodes.get(combination[1]);
// Skip triples that are shielded.
if (graph.isAdjacentTo(b, c)) {
continue;
}
if (isArrowpointAllowed1(b, a, knowledge) && isArrowpointAllowed1(c, a, knowledge)) {
if (!existsLocalSepsetWith(b, a, c, test, graph, depth)) {
graph.setEndpoint(b, a, Endpoint.ARROW);
graph.setEndpoint(c, a, Endpoint.ARROW);
TetradLogger.getInstance()
.log("colliderOriented", SearchLogUtils.colliderOrientedMsg(b, a, c));
}
}
}
}
TetradLogger.getInstance().log("info", "Finishing Collider Orientation.");
}
private void correlateExogenousVariables() {
Graph graph = getWorkbench().getGraph();
if (graph instanceof Dag) {
JOptionPane.showMessageDialog(
JOptionUtils.centeringComp(), "Cannot add bidirected edges to DAG's.");
return;
}
List<Node> nodes = graph.getNodes();
List<Node> exoNodes = new LinkedList<Node>();
for (int i = 0; i < nodes.size(); i++) {
Node node = nodes.get(i);
if (graph.isExogenous(node)) {
exoNodes.add(node);
}
}
for (int i = 0; i < exoNodes.size(); i++) {
loop:
for (int j = i + 1; j < exoNodes.size(); j++) {
Node node1 = exoNodes.get(i);
Node node2 = exoNodes.get(j);
List<Edge> edges = graph.getEdges(node1, node2);
for (int k = 0; k < edges.size(); k++) {
Edge edge = edges.get(k);
if (Edges.isBidirectedEdge(edge)) {
continue loop;
}
}
graph.addBidirectedEdge(node1, node2);
}
}
}
/**
* Greedy equivalence search: Start from the empty graph, add edges till model is significant.
* Then start deleting edges till a minimum is achieved.
*
* @return the resulting Pattern.
*/
public Graph search() {
Graph graph;
if (initialGraph == null) {
graph = new EdgeListGraphSingleConnections(getVariables());
} else {
graph = new EdgeListGraphSingleConnections(initialGraph);
}
fireGraphChange(graph);
buildIndexing(graph);
addRequiredEdges(graph);
topGraphs.clear();
storeGraph(graph);
List<Node> nodes = graph.getNodes();
long start = System.currentTimeMillis();
score = 0.0;
// Do forward search.
fes(graph, nodes);
// Do backward search.
bes(graph);
long endTime = System.currentTimeMillis();
this.elapsedTime = endTime - start;
this.logger.log("graph", "\nReturning this graph: " + graph);
this.logger.log("info", "Elapsed time = " + (elapsedTime) / 1000. + " s");
this.logger.flush();
return graph;
}
public List<Node> getNodes() {
return graph.getNodes();
}
/**
* Transforms a DAG represented in graph <code>graph</code> into a maximally directed pattern
* (PDAG) by modifying <code>g</code> itself. Based on the algorithm described in Chickering
* (2002) "Optimal structure identification with greedy search" Journal of Machine Learning
* Research. It works for both BayesNets and SEMs. R. Silva, June 2004
*/
public static void dagToPdag(Graph graph) {
// do topological sort on the nodes
Graph graphCopy = new EdgeListGraph(graph);
Node orderedNodes[] = new Node[graphCopy.getNodes().size()];
int count = 0;
while (graphCopy.getNodes().size() > 0) {
Set<Node> exogenousNodes = new HashSet<Node>();
for (Node next : graphCopy.getNodes()) {
if (graphCopy.isExogenous(next)) {
exogenousNodes.add(next);
orderedNodes[count++] = graph.getNode(next.getName());
}
}
graphCopy.removeNodes(new ArrayList<Node>(exogenousNodes));
}
// ordered edges - improvised, inefficient implementation
count = 0;
Edge edges[] = new Edge[graph.getNumEdges()];
boolean edgeOrdered[] = new boolean[graph.getNumEdges()];
Edge orderedEdges[] = new Edge[graph.getNumEdges()];
for (Edge edge : graph.getEdges()) {
edges[count++] = edge;
}
for (int i = 0; i < edges.length; i++) {
edgeOrdered[i] = false;
}
while (count > 0) {
for (Node orderedNode : orderedNodes) {
for (int k = orderedNodes.length - 1; k >= 0; k--) {
for (int q = 0; q < edges.length; q++) {
if (!edgeOrdered[q]
&& edges[q].getNode1() == orderedNodes[k]
&& edges[q].getNode2() == orderedNode) {
edgeOrdered[q] = true;
orderedEdges[orderedEdges.length - count] = edges[q];
count--;
}
}
}
}
}
// label edges
boolean compelledEdges[] = new boolean[graph.getNumEdges()];
boolean reversibleEdges[] = new boolean[graph.getNumEdges()];
for (int i = 0; i < graph.getNumEdges(); i++) {
compelledEdges[i] = false;
reversibleEdges[i] = false;
}
for (int i = 0; i < graph.getNumEdges(); i++) {
if (compelledEdges[i] || reversibleEdges[i]) {
continue;
}
Node x = orderedEdges[i].getNode1();
Node y = orderedEdges[i].getNode2();
for (int j = 0; j < orderedEdges.length; j++) {
if (orderedEdges[j].getNode2() == x && compelledEdges[j]) {
Node w = orderedEdges[j].getNode1();
if (!graph.isParentOf(w, y)) {
for (int k = 0; k < orderedEdges.length; k++) {
if (orderedEdges[k].getNode2() == y) {
compelledEdges[k] = true;
break;
}
}
} else {
for (int k = 0; k < orderedEdges.length; k++) {
if (orderedEdges[k].getNode1() == w && orderedEdges[k].getNode2() == y) {
compelledEdges[k] = true;
break;
}
}
}
}
if (compelledEdges[i]) {
break;
}
}
if (compelledEdges[i]) {
continue;
}
boolean foundZ = false;
for (Edge orderedEdge : orderedEdges) {
Node z = orderedEdge.getNode1();
if (z != x && orderedEdge.getNode2() == y && !graph.isParentOf(z, x)) {
compelledEdges[i] = true;
for (int k = i + 1; k < graph.getNumEdges(); k++) {
if (orderedEdges[k].getNode2() == y && !reversibleEdges[k]) {
compelledEdges[k] = true;
}
}
foundZ = true;
break;
}
}
if (!foundZ) {
reversibleEdges[i] = true;
for (int j = i + 1; j < orderedEdges.length; j++) {
if (!compelledEdges[j] && orderedEdges[j].getNode2() == y) {
reversibleEdges[j] = true;
}
}
}
}
// undirect edges that are reversible
for (int i = 0; i < reversibleEdges.length; i++) {
if (reversibleEdges[i]) {
graph.setEndpoint(orderedEdges[i].getNode1(), orderedEdges[i].getNode2(), Endpoint.TAIL);
graph.setEndpoint(orderedEdges[i].getNode2(), orderedEdges[i].getNode1(), Endpoint.TAIL);
}
}
}
