@Override
public @Nullable IDatum setPrior(@Nullable Object prior) {
if (prior instanceof double[]) {
return setPrior((double[]) prior);
}
if (prior instanceof Value) {
Value value = (Value) prior;
final DiscreteDomain domain = getDomain();
if (!domain.equals(value.getDomain())) {
// If domain does not match, create a new value with the correct domain. This ensures
// that indexing operations can be assumed to be correct for this variable.
prior = Value.create(domain, requireNonNull(value.getObject()));
}
}
return super.setPrior(prior);
}
/**
* Sets values for domain from datum.
*
* <p>
*
* @param domain discrete domain with size matching {@link #size()}.
* @param datum either an exact {@link Value}, another {@link DiscreteMessage} or other {@link
* IUnaryFactorFunction} used to evaluate energies for all possible discrete values.
* @since 0.08
*/
public void setFrom(DiscreteDomain domain, IDatum datum) {
if (datum instanceof DiscreteMessage) {
setFrom((DiscreteMessage) datum);
} else if (datum instanceof Value) {
Value value = (Value) datum;
if (domain.equals(value.getDomain())) {
setDeterministicIndex(value.getIndex());
} else {
setDeterministicIndex(domain.getIndex(value.getObject()));
}
} else {
IUnaryFactorFunction function = (IUnaryFactorFunction) datum;
assertSameSize(domain.size());
DiscreteValue value = Value.create(domain);
for (int i = domain.size(); --i >= 0; ) {
value.setIndex(i);
setEnergy(i, function.evalEnergy(value));
}
}
}
private @Nullable IDatum joinPriors(
JointDiscreteDomain<?> jointDomain, IDatum[] subdomainPriors) {
final JointDomainIndexer domains = jointDomain.getDomainIndexer();
final int dimensions = jointDomain.getDimensions();
boolean hasPrior = false;
int[] fixedIndices = new int[dimensions];
Arrays.fill(fixedIndices, -1);
for (int i = 0; i < dimensions; ++i) {
DiscreteDomain domain = domains.get(i);
IDatum prior = subdomainPriors[i];
if (prior != null) {
hasPrior = true;
if (prior instanceof Value) {
Value value = (Value) prior;
fixedIndices[i] =
domain.equals(value.getDomain())
? value.getIndex()
: domain.getIndex(value.getObject());
subdomainPriors[i] = new DiscreteEnergyMessage(domain, value);
} else {
DiscreteMessage msg =
prior instanceof DiscreteMessage
? (DiscreteMessage) prior
: new DiscreteWeightMessage(domain, prior);
subdomainPriors[i] = msg;
fixedIndices[i] = msg.toDeterministicValueIndex();
}
}
}
if (!hasPrior) {
// If none of the component variables has a prior, then neither will the joint variable.
return null;
}
boolean hasAllFixedPriors = true;
for (int i : fixedIndices) {
if (i < 0) {
hasAllFixedPriors = false;
break;
}
}
if (hasAllFixedPriors) {
// Return fixed value with appropriate joint index.
return Value.createWithIndex(jointDomain, domains.jointIndexFromIndices(fixedIndices));
}
int cardinality = jointDomain.size();
double[] energies = new double[cardinality];
int inner = 1, outer = cardinality;
for (int dim = 0; dim < dimensions; ++dim) {
final DiscreteDomain domain = domains.get(dim);
final DiscreteMessage prior = (DiscreteMessage) subdomainPriors[dim];
final int size = domain.size();
int i = 0;
outer /= size;
if (prior != null) {
for (int o = 0; o < outer; ++o) {
for (double energy : prior.getEnergies()) {
for (int r = 0; r < inner; ++r) {
energies[i++] += energy;
}
}
}
}
inner *= size;
}
return new DiscreteEnergyMessage(energies);
}
