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yap-6.3/packages/CLPBN/clpbn/bp/ElimGraph.cpp
2012-04-05 18:38:56 +01:00

314 lines
6.7 KiB
C++

#include <limits>
#include <fstream>
#include "ElimGraph.h"
ElimHeuristic ElimGraph::elimHeuristic_ = MIN_NEIGHBORS;
ElimGraph::ElimGraph (const vector<Factor*>& factors)
{
for (unsigned i = 0; i < factors.size(); i++) {
const VarIds& vids = factors[i]->arguments();
for (unsigned j = 0; j < vids.size() - 1; j++) {
EgNode* n1 = getEgNode (vids[j]);
if (n1 == 0) {
n1 = new EgNode (vids[j], factors[i]->range (j));
addNode (n1);
}
for (unsigned k = j + 1; k < vids.size(); k++) {
EgNode* n2 = getEgNode (vids[k]);
if (n2 == 0) {
n2 = new EgNode (vids[k], factors[i]->range (k));
addNode (n2);
}
if (neighbors (n1, n2) == false) {
addEdge (n1, n2);
}
}
}
if (vids.size() == 1) {
if (getEgNode (vids[0]) == 0) {
addNode (new EgNode (vids[0], factors[i]->range (0)));
}
}
}
setIndexes();
}
ElimGraph::~ElimGraph (void)
{
for (unsigned i = 0; i < nodes_.size(); i++) {
delete nodes_[i];
}
}
VarIds
ElimGraph::getEliminatingOrder (const VarIds& exclude)
{
VarIds elimOrder;
marked_.resize (nodes_.size(), false);
for (unsigned i = 0; i < exclude.size(); i++) {
assert (getEgNode (exclude[i]));
EgNode* node = getEgNode (exclude[i]);
marked_[*node] = true;
}
unsigned nVarsToEliminate = nodes_.size() - exclude.size();
for (unsigned i = 0; i < nVarsToEliminate; i++) {
EgNode* node = getLowestCostNode();
marked_[*node] = true;
elimOrder.push_back (node->varId());
connectAllNeighbors (node);
}
return elimOrder;
}
void
ElimGraph::print (void) const
{
for (unsigned i = 0; i < nodes_.size(); i++) {
cout << "node " << nodes_[i]->label() << " neighs:" ;
vector<EgNode*> neighs = nodes_[i]->neighbors();
for (unsigned 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: cannot open file to write at " ;
cerr << "Markov::exportToDotFile()" << endl;
abort();
}
out << "strict graph {" << endl;
for (unsigned i = 0; i < nodes_.size(); i++) {
if (showNeighborless || nodes_[i]->neighbors().size() != 0) {
out << '"' << nodes_[i]->label() << '"' << endl;
}
}
for (unsigned i = 0; i < highlightVarIds.size(); i++) {
EgNode* node =getEgNode (highlightVarIds[i]);
if (node) {
out << '"' << node->label() << '"' ;
out << " [shape=box3d]" << endl;
} else {
cout << "error: invalid variable id: " << highlightVarIds[i] << endl;
abort();
}
}
for (unsigned i = 0; i < nodes_.size(); i++) {
vector<EgNode*> neighs = nodes_[i]->neighbors();
for (unsigned j = 0; j < neighs.size(); j++) {
out << '"' << nodes_[i]->label() << '"' << " -- " ;
out << '"' << neighs[j]->label() << '"' << endl;
}
}
out << "}" << endl;
out.close();
}
VarIds
ElimGraph::getEliminationOrder (
const vector<Factor*> factors,
VarIds excludedVids)
{
ElimGraph graph (factors);
// graph.print();
// graph.exportToGraphViz ("_egg.dot");
return graph.getEliminatingOrder (excludedVids);
}
void
ElimGraph::addNode (EgNode* n)
{
nodes_.push_back (n);
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 = std::numeric_limits<unsigned>::max();
for (unsigned i = 0; i < nodes_.size(); i++) {
if (marked_[i]) continue;
unsigned cost = 0;
switch (elimHeuristic_) {
case MIN_NEIGHBORS:
cost = getNeighborsCost (nodes_[i]);
break;
case MIN_WEIGHT:
cost = getWeightCost (nodes_[i]);
break;
case MIN_FILL:
cost = getFillCost (nodes_[i]);
break;
case WEIGHTED_MIN_FILL:
cost = getWeightedFillCost (nodes_[i]);
break;
default:
assert (false);
}
if (cost < minCost) {
bestNode = nodes_[i];
minCost = cost;
}
}
assert (bestNode);
return bestNode;
}
unsigned
ElimGraph::getNeighborsCost (const EgNode* n) const
{
unsigned cost = 0;
const vector<EgNode*>& neighs = n->neighbors();
for (unsigned i = 0; i < neighs.size(); i++) {
if (marked_[*neighs[i]] == false) {
cost ++;
}
}
return cost;
}
unsigned
ElimGraph::getWeightCost (const EgNode* n) const
{
unsigned cost = 1;
const vector<EgNode*>& neighs = n->neighbors();
for (unsigned i = 0; i < neighs.size(); i++) {
if (marked_[*neighs[i]] == false) {
cost *= neighs[i]->range();
}
}
return cost;
}
unsigned
ElimGraph::getFillCost (const EgNode* n) const
{
unsigned cost = 0;
const vector<EgNode*>& neighs = n->neighbors();
if (neighs.size() > 0) {
for (unsigned i = 0; i < neighs.size() - 1; i++) {
if (marked_[*neighs[i]] == true) continue;
for (unsigned j = i+1; j < neighs.size(); j++) {
if (marked_[*neighs[j]] == true) continue;
if (!neighbors (neighs[i], neighs[j])) {
cost ++;
}
}
}
}
return cost;
}
unsigned
ElimGraph::getWeightedFillCost (const EgNode* n) const
{
unsigned cost = 0;
const vector<EgNode*>& neighs = n->neighbors();
if (neighs.size() > 0) {
for (unsigned i = 0; i < neighs.size() - 1; i++) {
if (marked_[*neighs[i]] == true) continue;
for (unsigned j = i+1; j < neighs.size(); j++) {
if (marked_[*neighs[j]] == true) continue;
if (!neighbors (neighs[i], neighs[j])) {
cost += neighs[i]->range() * neighs[j]->range();
}
}
}
}
return cost;
}
void
ElimGraph::connectAllNeighbors (const EgNode* n)
{
const vector<EgNode*>& neighs = n->neighbors();
if (neighs.size() > 0) {
for (unsigned i = 0; i < neighs.size() - 1; i++) {
if (marked_[*neighs[i]] == true) continue;
for (unsigned j = i+1; j < neighs.size(); j++) {
if (marked_[*neighs[j]] == true) continue;
if (!neighbors (neighs[i], neighs[j])) {
addEdge (neighs[i], neighs[j]);
}
}
}
}
}
bool
ElimGraph::neighbors (const EgNode* n1, const EgNode* n2) const
{
const vector<EgNode*>& neighs = n1->neighbors();
for (unsigned i = 0; i < neighs.size(); i++) {
if (neighs[i] == n2) {
return true;
}
}
return false;
}
void
ElimGraph::setIndexes (void)
{
for (unsigned i = 0; i < nodes_.size(); i++) {
nodes_[i]->setIndex (i);
}
}