void CFactorGraph::writeToFile( const char *filename ) const {
ofstream outfile;
outfile.open( filename );
if( outfile.is_open() ) {
outfile << *this;
outfile.close();
} else
DAI_THROW(CANNOT_WRITE_FILE);
}
Factor LC::belief (const VarSet &ns) const {
if( ns.size() == 0 )
return Factor();
else if( ns.size() == 1 )
return beliefV( findVar( *(ns.begin()) ) );
else {
DAI_THROW(BELIEF_NOT_AVAILABLE);
return Factor();
}
}
Factor ExactInf::belief( const VarSet &ns ) const {
if( ns.size() == 0 )
return Factor();
else if( ns.size() == 1 ) {
return beliefV( findVar( *(ns.begin()) ) );
} else {
size_t I;
for( I = 0; I < nrFactors(); I++ )
if( factor(I).vars() >> ns )
break;
if( I == nrFactors() )
DAI_THROW(BELIEF_NOT_AVAILABLE);
return beliefF(I).marginal(ns);
}
}
Real BBPCostFunction::evaluate( const InfAlg &ia, const vector<size_t> *stateP ) const {
Real cf = 0.0;
const FactorGraph &fg = ia.fg();
switch( (size_t)(*this) ) {
case CFN_BETHE_ENT: // ignores state
cf = -ia.logZ();
break;
case CFN_VAR_ENT: // ignores state
for( size_t i = 0; i < fg.nrVars(); i++ )
cf += -ia.beliefV(i).entropy();
break;
case CFN_FACTOR_ENT: // ignores state
for( size_t I = 0; I < fg.nrFactors(); I++ )
cf += -ia.beliefF(I).entropy();
break;
case CFN_GIBBS_B:
case CFN_GIBBS_B2:
case CFN_GIBBS_EXP: {
DAI_ASSERT( stateP != NULL );
vector<size_t> state = *stateP;
DAI_ASSERT( state.size() == fg.nrVars() );
for( size_t i = 0; i < fg.nrVars(); i++ ) {
Real b = ia.beliefV(i)[state[i]];
switch( (size_t)(*this) ) {
case CFN_GIBBS_B:
cf += b;
break;
case CFN_GIBBS_B2:
cf += b * b / 2.0;
break;
case CFN_GIBBS_EXP:
cf += exp( b );
break;
default:
DAI_THROW(UNKNOWN_ENUM_VALUE);
}
}
break;
} case CFN_GIBBS_B_FACTOR:
case CFN_GIBBS_B2_FACTOR:
case CFN_GIBBS_EXP_FACTOR: {
DAI_ASSERT( stateP != NULL );
vector<size_t> state = *stateP;
DAI_ASSERT( state.size() == fg.nrVars() );
for( size_t I = 0; I < fg.nrFactors(); I++ ) {
size_t x_I = getFactorEntryForState( fg, I, state );
Real b = ia.beliefF(I)[x_I];
switch( (size_t)(*this) ) {
case CFN_GIBBS_B_FACTOR:
cf += b;
break;
case CFN_GIBBS_B2_FACTOR:
cf += b * b / 2.0;
break;
case CFN_GIBBS_EXP_FACTOR:
cf += exp( b );
break;
default:
DAI_THROW(UNKNOWN_ENUM_VALUE);
}
}
break;
} default:
DAI_THROWE(UNKNOWN_ENUM_VALUE, "Unknown cost function " + std::string(*this));
}
return cf;
}