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yap-6.3/packages/CLPBN/clpbn/bp/FoveSolver.cpp
2012-04-13 15:47:41 +01:00

712 lines
17 KiB
C++

#include <algorithm>
#include <set>
#include "FoveSolver.h"
#include "Histogram.h"
#include "Util.h"
vector<LiftedOperator*>
LiftedOperator::getValidOps (
ParfactorList& pfList,
const Grounds& query)
{
vector<LiftedOperator*> validOps;
vector<SumOutOperator*> sumOutOps;
vector<CountingOperator*> countOps;
vector<GroundOperator*> groundOps;
sumOutOps = SumOutOperator::getValidOps (pfList, query);
countOps = CountingOperator::getValidOps (pfList);
groundOps = GroundOperator::getValidOps (pfList);
validOps.insert (validOps.end(), sumOutOps.begin(), sumOutOps.end());
validOps.insert (validOps.end(), countOps.begin(), countOps.end());
validOps.insert (validOps.end(), groundOps.begin(), groundOps.end());
return validOps;
}
void
LiftedOperator::printValidOps (
ParfactorList& pfList,
const Grounds& query)
{
vector<LiftedOperator*> validOps;
validOps = LiftedOperator::getValidOps (pfList, query);
for (unsigned i = 0; i < validOps.size(); i++) {
cout << "-> " << validOps[i]->toString() << endl;
delete validOps[i];
}
}
unsigned
SumOutOperator::getCost (void)
{
TinySet<unsigned> groupSet;
ParfactorList::const_iterator pfIter = pfList_.begin();
while (pfIter != pfList_.end()) {
if ((*pfIter)->containsGroup (group_)) {
vector<unsigned> groups = (*pfIter)->getAllGroups();
groupSet |= TinySet<unsigned> (groups);
}
++ pfIter;
}
unsigned cost = 1;
for (unsigned i = 0; i < groupSet.size(); i++) {
pfIter = pfList_.begin();
while (pfIter != pfList_.end()) {
if ((*pfIter)->containsGroup (groupSet[i])) {
int idx = (*pfIter)->indexOfGroup (groupSet[i]);
cost *= (*pfIter)->range (idx);
break;
}
++ pfIter;
}
}
return cost;
}
void
SumOutOperator::apply (void)
{
vector<ParfactorList::iterator> iters
= parfactorsWithGroup (pfList_, group_);
Parfactor* product = *(iters[0]);
pfList_.remove (iters[0]);
for (unsigned i = 1; i < iters.size(); i++) {
product->multiply (**(iters[i]));
pfList_.removeAndDelete (iters[i]);
}
if (product->nrArguments() == 1) {
delete product;
return;
}
int fIdx = product->indexOfGroup (group_);
LogVarSet excl = product->exclusiveLogVars (fIdx);
if (product->constr()->isCountNormalized (excl)) {
product->sumOut (fIdx);
pfList_.addShattered (product);
} else {
Parfactors pfs = FoveSolver::countNormalize (product, excl);
for (unsigned i = 0; i < pfs.size(); i++) {
pfs[i]->sumOut (fIdx);
pfList_.add (pfs[i]);
}
delete product;
}
}
vector<SumOutOperator*>
SumOutOperator::getValidOps (
ParfactorList& pfList,
const Grounds& query)
{
vector<SumOutOperator*> validOps;
set<unsigned> allGroups;
ParfactorList::const_iterator it = pfList.begin();
while (it != pfList.end()) {
const ProbFormulas& formulas = (*it)->arguments();
for (unsigned i = 0; i < formulas.size(); i++) {
allGroups.insert (formulas[i].group());
}
++ it;
}
set<unsigned>::const_iterator groupIt = allGroups.begin();
while (groupIt != allGroups.end()) {
if (validOp (*groupIt, pfList, query)) {
validOps.push_back (new SumOutOperator (*groupIt, pfList));
}
++ groupIt;
}
return validOps;
}
string
SumOutOperator::toString (void)
{
stringstream ss;
vector<ParfactorList::iterator> pfIters;
pfIters = parfactorsWithGroup (pfList_, group_);
int idx = (*pfIters[0])->indexOfGroup (group_);
ProbFormula f = (*pfIters[0])->argument (idx);
TupleSet tupleSet = (*pfIters[0])->constr()->tupleSet (f.logVars());
ss << "sum out " << f.functor() << "/" << f.arity();
ss << "|" << tupleSet << " (group " << group_ << ")";
ss << " [cost=" << getCost() << "]" << endl;
return ss.str();
}
bool
SumOutOperator::validOp (
unsigned group,
ParfactorList& pfList,
const Grounds& query)
{
vector<ParfactorList::iterator> pfIters;
pfIters = parfactorsWithGroup (pfList, group);
if (isToEliminate (*pfIters[0], group, query) == false) {
return false;
}
unordered_map<unsigned, unsigned> groupToRange;
for (unsigned i = 0; i < pfIters.size(); i++) {
int fIdx = (*pfIters[i])->indexOfGroup (group);
if ((*pfIters[i])->argument (fIdx).contains (
(*pfIters[i])->elimLogVars()) == false) {
return false;
}
vector<unsigned> ranges = (*pfIters[i])->ranges();
vector<unsigned> groups = (*pfIters[i])->getAllGroups();
for (unsigned i = 0; i < groups.size(); i++) {
unordered_map<unsigned, unsigned>::iterator it;
it = groupToRange.find (groups[i]);
if (it == groupToRange.end()) {
groupToRange.insert (make_pair (groups[i], ranges[i]));
} else {
if (it->second != ranges[i]) {
return false;
}
}
}
}
return true;
}
vector<ParfactorList::iterator>
SumOutOperator::parfactorsWithGroup (
ParfactorList& pfList,
unsigned group)
{
vector<ParfactorList::iterator> iters;
ParfactorList::iterator pflIt = pfList.begin();
while (pflIt != pfList.end()) {
if ((*pflIt)->containsGroup (group)) {
iters.push_back (pflIt);
}
++ pflIt;
}
return iters;
}
bool
SumOutOperator::isToEliminate (
Parfactor* g,
unsigned group,
const Grounds& query)
{
int fIdx = g->indexOfGroup (group);
const ProbFormula& formula = g->argument (fIdx);
bool toElim = true;
for (unsigned i = 0; i < query.size(); i++) {
if (formula.functor() == query[i].functor() &&
formula.arity() == query[i].arity()) {
g->constr()->moveToTop (formula.logVars());
if (g->constr()->containsTuple (query[i].args())) {
toElim = false;
break;
}
}
}
return toElim;
}
unsigned
CountingOperator::getCost (void)
{
unsigned cost = 0;
int fIdx = (*pfIter_)->indexOfLogVar (X_);
unsigned range = (*pfIter_)->range (fIdx);
unsigned size = (*pfIter_)->size() / range;
TinySet<unsigned> counts;
counts = (*pfIter_)->constr()->getConditionalCounts (X_);
for (unsigned i = 0; i < counts.size(); i++) {
cost += size * HistogramSet::nrHistograms (counts[i], range);
}
return cost;
}
void
CountingOperator::apply (void)
{
if ((*pfIter_)->constr()->isCountNormalized (X_)) {
(*pfIter_)->countConvert (X_);
} else {
Parfactor* pf = *pfIter_;
pfList_.remove (pfIter_);
Parfactors pfs = FoveSolver::countNormalize (pf, X_);
for (unsigned i = 0; i < pfs.size(); i++) {
unsigned condCount = pfs[i]->constr()->getConditionalCount (X_);
bool cartProduct = pfs[i]->constr()->isCarteesianProduct (
pfs[i]->countedLogVars() | X_);
if (condCount > 1 && cartProduct) {
pfs[i]->countConvert (X_);
}
pfList_.add (pfs[i]);
}
delete pf;
}
}
vector<CountingOperator*>
CountingOperator::getValidOps (ParfactorList& pfList)
{
vector<CountingOperator*> validOps;
ParfactorList::iterator it = pfList.begin();
while (it != pfList.end()) {
LogVarSet candidates = (*it)->uncountedLogVars();
for (unsigned i = 0; i < candidates.size(); i++) {
if (validOp (*it, candidates[i])) {
validOps.push_back (new CountingOperator (
it, candidates[i], pfList));
}
}
++ it;
}
return validOps;
}
string
CountingOperator::toString (void)
{
stringstream ss;
ss << "count convert " << X_ << " in " ;
ss << (*pfIter_)->getLabel();
ss << " [cost=" << getCost() << "]" << endl;
Parfactors pfs = FoveSolver::countNormalize (*pfIter_, X_);
if ((*pfIter_)->constr()->isCountNormalized (X_) == false) {
for (unsigned i = 0; i < pfs.size(); i++) {
ss << " º " << pfs[i]->getLabel() << endl;
}
}
for (unsigned i = 0; i < pfs.size(); i++) {
delete pfs[i];
}
return ss.str();
}
bool
CountingOperator::validOp (Parfactor* g, LogVar X)
{
if (g->nrFormulas (X) != 1) {
return false;
}
int fIdx = g->indexOfLogVar (X);
if (g->argument (fIdx).isCounting()) {
return false;
}
bool countNormalized = g->constr()->isCountNormalized (X);
if (countNormalized) {
unsigned condCount = g->constr()->getConditionalCount (X);
bool cartProduct = g->constr()->isCarteesianProduct (
g->countedLogVars() | X);
if (condCount == 1 || cartProduct == false) {
return false;
}
}
return true;
}
unsigned
GroundOperator::getCost (void)
{
unsigned cost = 0;
bool isCountingLv = (*pfIter_)->countedLogVars().contains (X_);
if (isCountingLv) {
int fIdx = (*pfIter_)->indexOfLogVar (X_);
unsigned currSize = (*pfIter_)->size();
unsigned nrHists = (*pfIter_)->range (fIdx);
unsigned range = (*pfIter_)->argument (fIdx).range();
unsigned nrSymbols = (*pfIter_)->constr()->getConditionalCount (X_);
cost = (currSize / nrHists) * (std::pow (range, nrSymbols));
} else {
cost = (*pfIter_)->constr()->nrSymbols (X_) * (*pfIter_)->size();
}
return cost;
}
void
GroundOperator::apply (void)
{
bool countedLv = (*pfIter_)->countedLogVars().contains (X_);
Parfactor* pf = *pfIter_;
pfList_.remove (pfIter_);
if (countedLv) {
pf->fullExpand (X_);
pfList_.add (pf);
} else {
ConstraintTrees cts = pf->constr()->ground (X_);
for (unsigned i = 0; i < cts.size(); i++) {
pfList_.add (new Parfactor (pf, cts[i]));
}
delete pf;
}
}
vector<GroundOperator*>
GroundOperator::getValidOps (ParfactorList& pfList)
{
vector<GroundOperator*> validOps;
ParfactorList::iterator pfIter = pfList.begin();
while (pfIter != pfList.end()) {
LogVarSet set = (*pfIter)->logVarSet();
for (unsigned i = 0; i < set.size(); i++) {
if ((*pfIter)->constr()->isSingleton (set[i]) == false) {
validOps.push_back (new GroundOperator (pfIter, set[i], pfList));
}
}
++ pfIter;
}
return validOps;
}
string
GroundOperator::toString (void)
{
stringstream ss;
((*pfIter_)->countedLogVars().contains (X_))
? ss << "full expanding "
: ss << "grounding " ;
ss << X_ << " in " << (*pfIter_)->getLabel();
ss << " [cost=" << getCost() << "]" << endl;
return ss.str();
}
Params
FoveSolver::getPosterioriOf (const Ground& query)
{
return getJointDistributionOf ({query});
}
Params
FoveSolver::getJointDistributionOf (const Grounds& query)
{
runSolver (query);
(*pfList_.begin())->normalize();
Params params = (*pfList_.begin())->params();
if (Globals::logDomain) {
Util::fromLog (params);
}
return params;
}
void
FoveSolver::absorveEvidence (
ParfactorList& pfList,
ObservedFormulas& obsFormulas)
{
for (unsigned i = 0; i < obsFormulas.size(); i++) {
Parfactors newPfs;
ParfactorList::iterator it = pfList.begin();
while (it != pfList.end()) {
Parfactor* pf = *it;
it = pfList.remove (it);
Parfactors absorvedPfs = absorve (obsFormulas[i], pf);
if (absorvedPfs.empty() == false) {
if (absorvedPfs.size() == 1 && absorvedPfs[0] == 0) {
// just remove pf;
} else {
Util::addToVector (newPfs, absorvedPfs);
}
delete pf;
} else {
it = pfList.insertShattered (it, pf);
++ it;
}
}
pfList.add (newPfs);
}
if (Constants::DEBUG >= 2 && obsFormulas.empty() == false) {
Util::printAsteriskLine();
cout << "AFTER EVIDENCE ABSORVED" << endl;
for (unsigned i = 0; i < obsFormulas.size(); i++) {
cout << " -> " << obsFormulas[i] << endl;
}
Util::printAsteriskLine();
pfList.print();
}
}
Parfactors
FoveSolver::countNormalize (
Parfactor* g,
const LogVarSet& set)
{
Parfactors normPfs;
if (set.empty()) {
normPfs.push_back (new Parfactor (*g));
} else {
ConstraintTrees normCts = g->constr()->countNormalize (set);
for (unsigned i = 0; i < normCts.size(); i++) {
normPfs.push_back (new Parfactor (g, normCts[i]));
}
}
return normPfs;
}
void
FoveSolver::runSolver (const Grounds& query)
{
shatterAgainstQuery (query);
runWeakBayesBall (query);
while (true) {
if (Constants::DEBUG >= 2) {
Util::printDashedLine();
pfList_.print();
LiftedOperator::printValidOps (pfList_, query);
}
LiftedOperator* op = getBestOperation (query);
if (op == 0) {
break;
}
if (Constants::DEBUG >= 2) {
cout << "best operation: " << op->toString() << endl;
}
op->apply();
delete op;
}
assert (pfList_.size() > 0);
if (pfList_.size() > 1) {
ParfactorList::iterator pfIter = pfList_.begin();
pfIter ++;
while (pfIter != pfList_.end()) {
(*pfList_.begin())->multiply (**pfIter);
++ pfIter;
}
}
(*pfList_.begin())->reorderAccordingGrounds (query);
}
LiftedOperator*
FoveSolver::getBestOperation (const Grounds& query)
{
unsigned bestCost = Util::maxUnsigned();
LiftedOperator* bestOp = 0;
vector<LiftedOperator*> validOps;
validOps = LiftedOperator::getValidOps (pfList_, query);
for (unsigned i = 0; i < validOps.size(); i++) {
unsigned cost = validOps[i]->getCost();
if ((bestOp == 0) || (cost < bestCost)) {
bestOp = validOps[i];
bestCost = cost;
}
}
for (unsigned i = 0; i < validOps.size(); i++) {
if (validOps[i] != bestOp) {
delete validOps[i];
}
}
return bestOp;
}
void
FoveSolver::runWeakBayesBall (const Grounds& query)
{
queue<unsigned> todo; // groups to process
set<unsigned> done; // processed or in queue
for (unsigned i = 0; i < query.size(); i++) {
ParfactorList::iterator it = pfList_.begin();
while (it != pfList_.end()) {
int group = (*it)->findGroup (query[i]);
if (group != -1) {
todo.push (group);
done.insert (group);
break;
}
++ it;
}
}
set<Parfactor*> requiredPfs;
while (todo.empty() == false) {
unsigned group = todo.front();
ParfactorList::iterator it = pfList_.begin();
while (it != pfList_.end()) {
if (Util::contains (requiredPfs, *it) == false &&
(*it)->containsGroup (group)) {
vector<unsigned> groups = (*it)->getAllGroups();
for (unsigned i = 0; i < groups.size(); i++) {
if (Util::contains (done, groups[i]) == false) {
todo.push (groups[i]);
done.insert (groups[i]);
}
}
requiredPfs.insert (*it);
}
++ it;
}
todo.pop();
}
ParfactorList::iterator it = pfList_.begin();
while (it != pfList_.end()) {
if (Util::contains (requiredPfs, *it) == false) {
it = pfList_.removeAndDelete (it);
} else {
++ it;
}
}
if (Constants::DEBUG >= 2) {
Util::printHeader ("REQUIRED PARFACTORS");
pfList_.print();
}
}
void
FoveSolver::shatterAgainstQuery (const Grounds& query)
{
for (unsigned i = 0; i < query.size(); i++) {
if (query[i].isAtom()) {
continue;
}
bool found = false;
Parfactors newPfs;
ParfactorList::iterator it = pfList_.begin();
while (it != pfList_.end()) {
if ((*it)->containsGround (query[i])) {
found = true;
std::pair<ConstraintTree*, ConstraintTree*> split =
(*it)->constr()->split (query[i].args(), query[i].arity());
ConstraintTree* commCt = split.first;
ConstraintTree* exclCt = split.second;
newPfs.push_back (new Parfactor (*it, commCt));
if (exclCt->empty() == false) {
newPfs.push_back (new Parfactor (*it, exclCt));
} else {
delete exclCt;
}
it = pfList_.removeAndDelete (it);
} else {
++ it;
}
}
if (found == false) {
cerr << "error: could not find a parfactor with ground " ;
cerr << "`" << query[i] << "'" << endl;
exit (0);
}
pfList_.add (newPfs);
}
if (Constants::DEBUG >= 2) {
cout << endl;
Util::printAsteriskLine();
cout << "SHATTERED AGAINST THE QUERY" << endl;
for (unsigned i = 0; i < query.size(); i++) {
cout << " -> " << query[i] << endl;
}
Util::printAsteriskLine();
pfList_.print();
}
}
Parfactors
FoveSolver::absorve (
ObservedFormula& obsFormula,
Parfactor* g)
{
Parfactors absorvedPfs;
const ProbFormulas& formulas = g->arguments();
for (unsigned i = 0; i < formulas.size(); i++) {
if (obsFormula.functor() == formulas[i].functor() &&
obsFormula.arity() == formulas[i].arity()) {
if (obsFormula.isAtom()) {
if (formulas.size() > 1) {
g->absorveEvidence (formulas[i], obsFormula.evidence());
} else {
// hack to erase parfactor g
absorvedPfs.push_back (0);
}
break;
}
g->constr()->moveToTop (formulas[i].logVars());
std::pair<ConstraintTree*, ConstraintTree*> res
= g->constr()->split (&(obsFormula.constr()), formulas[i].arity());
ConstraintTree* commCt = res.first;
ConstraintTree* exclCt = res.second;
if (commCt->empty() == false) {
if (formulas.size() > 1) {
LogVarSet excl = g->exclusiveLogVars (i);
Parfactors countNormPfs = countNormalize (g, excl);
for (unsigned j = 0; j < countNormPfs.size(); j++) {
countNormPfs[j]->absorveEvidence (
formulas[i], obsFormula.evidence());
absorvedPfs.push_back (countNormPfs[j]);
}
} else {
delete commCt;
}
if (exclCt->empty() == false) {
absorvedPfs.push_back (new Parfactor (g, exclCt));
} else {
delete exclCt;
}
if (absorvedPfs.empty()) {
// hack to erase parfactor g
absorvedPfs.push_back (0);
}
break;
} else {
delete commCt;
delete exclCt;
}
}
}
return absorvedPfs;
}