SGVector< float64_t > CFactorGraphModel::get_joint_feature_vector(int32_t feat_idx, CStructuredData* y)
{
// factor graph instance
CFactorGraphFeatures* mf = CFactorGraphFeatures::obtain_from_generic(m_features);
CFactorGraph* fg = mf->get_sample(feat_idx);
// ground truth states
CFactorGraphObservation* fg_states = CFactorGraphObservation::obtain_from_generic(y);
SGVector<int32_t> states = fg_states->get_data();
// initialize psi
SGVector<float64_t> psi(get_dim());
psi.zero();
// construct unnormalized psi
CDynamicObjectArray* facs = fg->get_factors();
for (int32_t fi = 0; fi < facs->get_num_elements(); ++fi)
{
CFactor* fac = dynamic_cast<CFactor*>(facs->get_element(fi));
CTableFactorType* ftype = fac->get_factor_type();
int32_t id = ftype->get_type_id();
SGVector<int32_t> w_map = get_params_mapping(id);
ASSERT(w_map.size() == ftype->get_w_dim());
SGVector<float64_t> dat = fac->get_data();
int32_t dat_size = dat.size();
ASSERT(w_map.size() == dat_size * ftype->get_num_assignments());
int32_t ei = ftype->index_from_universe_assignment(states, fac->get_variables());
for (int32_t di = 0; di < dat_size; di++)
psi[w_map[ei*dat_size + di]] += dat[di];
SG_UNREF(ftype);
SG_UNREF(fac);
}
// negation (-E(x,y) = <w,phi(x,y)>)
psi.scale(-1.0);
SG_UNREF(facs);
SG_UNREF(fg);
return psi;
}
