private MaxMinAssocResult maxMinAssoc(Node t, List<Node> pc, List<Node> indepOfT) {
Node f = null;
List<Node> maxAssocSet = null;
double maxAssoc = 0.0;
for (Node v : variables) {
if (t == v) continue;
if (pc.contains(v)) continue;
if (indepOfT.contains(v)) {
continue;
}
List<Node> minAssoc = minAssoc(v, t, pc);
double assoc = association(v, t, minAssoc);
// If v is conditionally independent of t, don't consider it
// again. Note if this code is right, then we have to use the
// association test as an independence test... ugh.
if (assoc < 1.0 - independenceTest.getAlpha()) {
indepOfT.add(v);
}
if (assoc > maxAssoc) {
maxAssocSet = minAssoc;
maxAssoc = assoc;
f = v;
}
}
return new MaxMinAssocResult(f, maxAssocSet);
}
private void backwardsConditioning(List<Node> pc, Node target) {
for (Node x : new LinkedList<>(pc)) {
List<Node> _pc = new LinkedList<>(pc);
_pc.remove(x);
_pc.remove(target);
List<Node> minAssoc = minAssoc(x, target, _pc);
numIndTests++;
if (independenceTest.isIndependent(x, target, minAssoc)) {
pc.remove(x);
}
}
}
/**
* Constructs.
*
* @param test The independence test used in the search.
* @param depth The maximum number of variables conditioned on.
* @param symmetric True if the symmetric algorithm is to be used.
*/
public Mmmb(IndependenceTest test, int depth, boolean symmetric) {
if (test == null) {
throw new NullPointerException();
}
if (depth < -1) {
throw new IllegalArgumentException();
}
this.independenceTest = test;
this.variables = test.getVariables();
this.depth = depth;
this.symmetric = symmetric;
pc = new HashMap<>();
trimmed = new HashSet<>();
}
private List<Node> mmpc(Node t) {
List<Node> pc = new LinkedList<>();
boolean pcIncreased = true;
// First optimization: Don't consider adding again variables that have
// already been found independent of t.
List<Node> indepOfT = new LinkedList<>();
// Phase 1
while (pcIncreased) {
pcIncreased = false;
MaxMinAssocResult ret = maxMinAssoc(t, pc, indepOfT);
Node f = ret.getNode();
List<Node> assocSet = ret.getAssocSet();
if (f == null) {
break;
}
numIndTests++;
if (!independenceTest.isIndependent(f, t, assocSet)) {
pcIncreased = true;
pc.add(f);
}
}
// Phase 2.
backwardsConditioning(pc, t);
TetradLogger.getInstance().log("details", "PC(" + t + ") = " + pc);
// System.out.println("PC(" + t + ") = " + pc);
return pc;
}
private double association(Node x, Node target, List<Node> s) {
numIndTests++;
independenceTest.isIndependent(x, target, s);
return 1.0 - independenceTest.getPValue();
}
private List<Node> mmmb(Node t) {
// MB <- {}
Set<Node> mb = new HashSet<>();
Set<Node> _pcpc = new HashSet<>();
for (Node node : getPc(t)) {
List<Node> f = getPc(node);
this.pc.put(node, f);
_pcpc.addAll(f);
}
List<Node> pcpc = new LinkedList<>(_pcpc);
Set<Node> currentMb = new HashSet<>(getPc(t));
currentMb.addAll(pcpc);
currentMb.remove(t);
HashSet<Node> diff = new HashSet<>(currentMb);
diff.removeAll(getPc(t));
diff.remove(t);
// for each x in PCPC \ PC
for (Node x : diff) {
List<Node> s = null;
// Find an S such PC such that x _||_ t | S
DepthChoiceGenerator generator = new DepthChoiceGenerator(pcpc.size(), depth);
int[] choice;
while ((choice = generator.next()) != null) {
List<Node> _s = new LinkedList<>();
for (int index : choice) {
_s.add(pcpc.get(index));
}
numIndTests++;
if (independenceTest.isIndependent(t, x, _s)) {
s = _s;
break;
}
}
if (s == null) {
System.out.println("S not found.");
// mb.add(x);
continue;
}
// y_set <- {y in PC(t) : x in PC(y)}
Set<Node> ySet = new HashSet<>();
for (Node y : getPc(t)) {
if (this.pc.get(y).contains(x)) {
ySet.add(y);
}
}
// For each y in y_set
for (Node y : ySet) {
if (x == y) continue;
List<Node> _s = new LinkedList<>(s);
_s.add(y);
// If x NOT _||_ t | S U {y}
numIndTests++;
if (!independenceTest.isIndependent(t, x, _s)) {
mb.add(x);
break;
}
}
}
mb.addAll(getPc(t));
return new LinkedList<>(mb);
}
