com.expleague.ml.models.pgm.SimplePGM Maven / Gradle / Ivy
package com.expleague.ml.models.pgm;
import com.expleague.commons.math.MathTools;
import com.expleague.commons.math.vectors.Mx;
import com.expleague.commons.math.vectors.Vec;
import com.expleague.commons.math.vectors.VecTools;
import com.expleague.commons.random.FastRandom;
import com.expleague.commons.math.Func;
import gnu.trove.list.array.TByteArrayList;
import gnu.trove.list.array.TDoubleArrayList;
import gnu.trove.list.array.TIntArrayList;
import java.util.*;
import java.util.function.Predicate;
import java.util.stream.IntStream;
/**
* User: solar
* Date: 27.01.14
* Time: 10:19
*/
public class SimplePGM extends Func.Stub implements ProbabilisticGraphicalModel {
public static final double KNOWN_ROUTES_PROBABILITY = 0.999;
public static final double MIN_SINGLE_ROUTE_PROBABILITY = 0.000001;
public final Mx topology;
protected final boolean[] isFinalState;
private final byte[] nodes;
private final MyLWRoute[] routes;
public double meanERouteLength = 0;
private double knownRoutesProBab;
public SimplePGM(Mx topology) {
topology = VecTools.copy(topology);
isFinalState = new boolean[topology.rows()];
for (int i = 0; i < topology.rows(); i++) {
VecTools.normalizeL1(topology.row(i));
if (VecTools.norm1(topology.row(i)) < MathTools.EPSILON)
isFinalState[i] = true;
}
this.topology = topology;
knownRoutesProBab = 0.;
final List order = new LinkedList<>();
final TreeSet increment = new TreeSet<>((o1, o2) -> o2.p() >= o1.p() ? 1 : -1);
order.add(new MyRoute(new byte[]{0}, 1.));
double minProbab = 0.01;
final TByteArrayList nodes = new TByteArrayList();
final TIntArrayList boundaries = new TIntArrayList();
final TDoubleArrayList probabs = new TDoubleArrayList();
while (knownRoutesProBab < KNOWN_ROUTES_PROBABILITY && minProbab > MIN_SINGLE_ROUTE_PROBABILITY) {
boolean hasInc = false;
final ListIterator it = order.listIterator();
increment.clear();
while(it.hasNext()) {
final MyRoute next = it.next();
if (next.maxClosedProbab > minProbab) {
next.disclose(topology, increment, minProbab);
hasInc = true;
}
if (next.maxClosedProbab == 0.) {
if (isFinal(next.last())) {
probabs.add(next.probab);
nodes.addAll(next.route);
boundaries.add(nodes.size());
knownRoutesProBab += next.probab;
}
it.remove();
}
if (!increment.isEmpty() && (!it.hasNext() || (order.get(it.nextIndex()).p() < increment.first().p()))) {
it.add(increment.pollFirst());
it.previous();
}
}
if (!hasInc)
minProbab /= 2.;
}
this.nodes = nodes.toArray();
routes = new MyLWRoute[boundaries.size()];
int start = 0;
for (int i = 0; i < boundaries.size(); i++) {
routes[i] = new MyLWRoute(start, start = boundaries.get(i), probabs.get(i));
}
System.out.println("Routes built: " + boundaries.size() + " weight: " + knownRoutesProBab);
}
public SimplePGM(final Mx next, final double meanLen) {
this(next);
this.meanERouteLength = meanLen;
}
/** need to change this to prefix tree which is way faster */
public void visit(final Predicate act, final int... controlPoints) {
visit(route -> {
int index = 0;
int controlPoint = controlPoints[index];
for (int t = 0; t < route.length(); t++) {
if (route.dst(t) == controlPoint) {
index++;
if (index == controlPoints.length)
return act.test(route);
controlPoint = controlPoints[index];
}
}
return false;
});
}
@Override
public void visit(final Predicate act) {
for (final MyLWRoute route : routes) {
if (act.test(route))
return;
}
}
@Override
public double p(final int... controlPoints) {
final double[] result = new double[]{0.};
visit(route -> {
result[0] += route.p();
return false;
}, controlPoints);
return result[0];
}
@Override
public double value(final Vec x) {
return p(extractControlPoints(x));
}
public int[] extractControlPoints(final Vec x) {
final TIntArrayList toInt = new TIntArrayList(x.dim() + 1);
toInt.add(0);
for (int i = 0; i < x.dim(); i++) {
final double next = x.get(i);
if (next < 1 || next >= topology.rows())
break;
toInt.add((int)next - 1);
}
return toInt.toArray();
}
@Override
public Route next(final FastRandom rng) {
final TByteArrayList result = new TByteArrayList(100);
byte next = 0;
double p = 1;
while (true) {
final Vec trans = topology.row(next);
next = (byte)rng.nextSimple(trans);
p *= trans.get(next);
result.add(next);
if (isFinalState[next])
break;
}
return new MyRoute(result.toArray(), p);
}
@Override
public int dim() {
return topology.rows();
}
@Override
public boolean isFinal(final int node) {
return isFinalState[node];
}
@Override
public int knownRoutesCount() {
return routes.length;
}
@Override
public Route knownRoute(final int randRoute) {
return routes[randRoute];
}
@Override
public double knownRoutesWeight() {
return knownRoutesProBab;
}
public class MyLWRoute implements Route {
private final int start;
private final int end;
private final double probab;
private MyLWRoute(final int start, final int end, final double probab) {
this.start = start;
this.end = end;
this.probab = probab;
}
@Override
public double p() {
return probab;
}
@Override
public int last() {
return nodes[end - 1];
}
@Override
public int length() {
return end - start;
}
@Override
public ProbabilisticGraphicalModel dstOwner(final int stepNo) {
return SimplePGM.this;
}
@Override
public int dst(final int stepNo) {
return nodes[stepNo + start];
}
@Override
public IntStream states() {
return IntStream.range(0, length()).map(idx -> nodes[idx + start]);
}
}
public class MyRoute implements Route {
private final byte[] route;
private final double probab;
private double maxClosedProbab;
public MyRoute(final byte[] route, final double probab) {
this.route = route;
this.probab = probab;
final byte last = route[route.length - 1];
maxClosedProbab = 0.;
for (int next = 0; next < topology.columns(); next++) {
maxClosedProbab = Math.max(probab * topology.get(last, next), maxClosedProbab);
}
}
void disclose(final Mx topology, final TreeSet container, final double minProbab) {
final double lowerBound = maxClosedProbab;
maxClosedProbab = 0.;
for (int next = 0; next < topology.columns(); next++) {
final double nextProbab = p() * topology.get(last(), next);
if (nextProbab > lowerBound) // already disclosed
continue;
if (nextProbab < minProbab) {
maxClosedProbab = Math.max(nextProbab, maxClosedProbab);
continue;
}
final byte[] nextRouteB = new byte[route.length + 1];
System.arraycopy(route, 0, nextRouteB, 0, route.length);
nextRouteB[nextRouteB.length - 1] = (byte)next;
container.add(new MyRoute(nextRouteB, nextProbab));
}
}
@Override
public double p() {
return probab;
}
@Override
public int last() {
return route[route.length - 1];
}
@Override
public int length() {
return route.length;
}
@Override
public ProbabilisticGraphicalModel dstOwner(final int stepNo) {
return SimplePGM.this;
}
@Override
public int dst(final int stepNo) {
return route[stepNo];
}
@Override
public IntStream states() {
return IntStream.range(0, length()).map(idx -> route[idx]);
}
}
}
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