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yap-6.3/packages/CLPBN/horus/ElimGraph.cpp
2012-12-27 15:44:40 +00:00

239 lines
5.6 KiB
C++

#include <fstream>
#include "ElimGraph.h"
ElimHeuristic ElimGraph::elimHeuristic_ = MIN_NEIGHBORS;
ElimGraph::ElimGraph (const vector<Factor*>& factors)
{
for (size_t i = 0; i < factors.size(); i++) {
if (factors[i]) {
const VarIds& args = factors[i]->arguments();
for (size_t j = 0; j < args.size() - 1; j++) {
EgNode* n1 = getEgNode (args[j]);
if (!n1) {
n1 = new EgNode (args[j], factors[i]->range (j));
addNode (n1);
}
for (size_t k = j + 1; k < args.size(); k++) {
EgNode* n2 = getEgNode (args[k]);
if (!n2) {
n2 = new EgNode (args[k], factors[i]->range (k));
addNode (n2);
}
if (!neighbors (n1, n2)) {
addEdge (n1, n2);
}
}
}
if (args.size() == 1 && !getEgNode (args[0])) {
addNode (new EgNode (args[0], factors[i]->range (0)));
}
}
}
}
ElimGraph::~ElimGraph (void)
{
for (size_t i = 0; i < nodes_.size(); i++) {
delete nodes_[i];
}
}
VarIds
ElimGraph::getEliminatingOrder (const VarIds& excludedVids)
{
VarIds elimOrder;
unmarked_.reserve (nodes_.size());
for (size_t i = 0; i < nodes_.size(); i++) {
if (Util::contains (excludedVids, nodes_[i]->varId()) == false) {
unmarked_.insert (nodes_[i]);
}
}
size_t nrVarsToEliminate = nodes_.size() - excludedVids.size();
for (size_t i = 0; i < nrVarsToEliminate; i++) {
EgNode* node = getLowestCostNode();
unmarked_.remove (node);
const EGNeighs& neighs = node->neighbors();
for (size_t j = 0; j < neighs.size(); j++) {
neighs[j]->removeNeighbor (node);
}
elimOrder.push_back (node->varId());
connectAllNeighbors (node);
}
return elimOrder;
}
void
ElimGraph::print (void) const
{
for (size_t i = 0; i < nodes_.size(); i++) {
cout << "node " << nodes_[i]->label() << " neighs:" ;
EGNeighs neighs = nodes_[i]->neighbors();
for (size_t j = 0; j < neighs.size(); j++) {
cout << " " << neighs[j]->label();
}
cout << endl;
}
}
void
ElimGraph::exportToGraphViz (
const char* fileName,
bool showNeighborless,
const VarIds& highlightVarIds) const
{
ofstream out (fileName);
if (!out.is_open()) {
cerr << "Error: couldn't open file '" << fileName << "'." ;
return;
}
out << "strict graph {" << endl;
for (size_t i = 0; i < nodes_.size(); i++) {
if (showNeighborless || nodes_[i]->neighbors().empty() == false) {
out << '"' << nodes_[i]->label() << '"' << endl;
}
}
for (size_t i = 0; i < highlightVarIds.size(); i++) {
EgNode* node =getEgNode (highlightVarIds[i]);
if (node) {
out << '"' << node->label() << '"' ;
out << " [shape=box3d]" << endl;
} else {
cerr << "Error: invalid variable id: " << highlightVarIds[i] << "." ;
cerr << endl;
exit (EXIT_FAILURE);
}
}
for (size_t i = 0; i < nodes_.size(); i++) {
EGNeighs neighs = nodes_[i]->neighbors();
for (size_t j = 0; j < neighs.size(); j++) {
out << '"' << nodes_[i]->label() << '"' << " -- " ;
out << '"' << neighs[j]->label() << '"' << endl;
}
}
out << "}" << endl;
out.close();
}
VarIds
ElimGraph::getEliminationOrder (
const Factors& factors,
VarIds excludedVids)
{
if (elimHeuristic_ == ElimHeuristic::SEQUENTIAL) {
VarIds allVids;
Factors::const_iterator first = factors.begin();
Factors::const_iterator end = factors.end();
for (; first != end; ++first) {
Util::addToVector (allVids, (*first)->arguments());
}
TinySet<VarId> elimOrder (allVids);
elimOrder -= TinySet<VarId> (excludedVids);
return elimOrder.elements();
}
ElimGraph graph (factors);
return graph.getEliminatingOrder (excludedVids);
}
void
ElimGraph::addNode (EgNode* n)
{
nodes_.push_back (n);
n->setIndex (nodes_.size() - 1);
varMap_.insert (make_pair (n->varId(), n));
}
EgNode*
ElimGraph::getEgNode (VarId vid) const
{
unordered_map<VarId, EgNode*>::const_iterator it;
it = varMap_.find (vid);
return (it != varMap_.end()) ? it->second : 0;
}
EgNode*
ElimGraph::getLowestCostNode (void) const
{
EgNode* bestNode = 0;
unsigned minCost = Util::maxUnsigned();
EGNeighs::const_iterator it;
switch (elimHeuristic_) {
case MIN_NEIGHBORS: {
for (it = unmarked_.begin(); it != unmarked_.end(); ++ it) {
unsigned cost = getNeighborsCost (*it);
if (cost < minCost) {
bestNode = *it;
minCost = cost;
}
}}
break;
case MIN_WEIGHT: {
for (it = unmarked_.begin(); it != unmarked_.end(); ++ it) {
unsigned cost = getWeightCost (*it);
if (cost < minCost) {
bestNode = *it;
minCost = cost;
}
}}
break;
case MIN_FILL: {
for (it = unmarked_.begin(); it != unmarked_.end(); ++ it) {
unsigned cost = getFillCost (*it);
if (cost < minCost) {
bestNode = *it;
minCost = cost;
}
}}
break;
case WEIGHTED_MIN_FILL: {
for (it = unmarked_.begin(); it != unmarked_.end(); ++ it) {
unsigned cost = getWeightedFillCost (*it);
if (cost < minCost) {
bestNode = *it;
minCost = cost;
}
}}
break;
default:
assert (false);
}
assert (bestNode);
return bestNode;
}
void
ElimGraph::connectAllNeighbors (const EgNode* n)
{
const EGNeighs& neighs = n->neighbors();
if (neighs.size() > 0) {
for (size_t i = 0; i < neighs.size() - 1; i++) {
for (size_t j = i + 1; j < neighs.size(); j++) {
if (!neighbors (neighs[i], neighs[j])) {
addEdge (neighs[i], neighs[j]);
}
}
}
}
}