diff options
Diffstat (limited to 'decoder/decoder.cc')
| -rw-r--r-- | decoder/decoder.cc | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/decoder/decoder.cc b/decoder/decoder.cc index 95ff6270..b7774acc 100644 --- a/decoder/decoder.cc +++ b/decoder/decoder.cc @@ -141,12 +141,13 @@ inline shared_ptr<FsaFeatureFunction> make_fsa_ff(string const& ffp,bool verbose // and then prune the resulting (rescored) hypergraph. All feature values from previous // passes are carried over into subsequent passes (where they may have different weights). struct RescoringPass { - RescoringPass() : density_prune(), beam_prune() {} + RescoringPass() : fid_summary(), density_prune(), beam_prune() {} shared_ptr<ModelSet> models; shared_ptr<IntersectionConfiguration> inter_conf; vector<const FeatureFunction*> ffs; shared_ptr<Weights> w; // null == use previous weights vector<double> weight_vector; + int fid_summary; // 0 == no summary feature double density_prune; // 0 == don't density prune double beam_prune; // 0 == don't beam prune }; @@ -155,6 +156,7 @@ ostream& operator<<(ostream& os, const RescoringPass& rp) { os << "[num_fn=" << rp.ffs.size(); if (rp.inter_conf) { os << " int_alg=" << *rp.inter_conf; } if (rp.w) os << " new_weights"; + if (rp.fid_summary) os << " summary_feature=" << FD::Convert(rp.fid_summary); if (rp.density_prune) os << " density_prune=" << rp.density_prune; if (rp.beam_prune) os << " beam_prune=" << rp.beam_prune; os << ']'; @@ -361,18 +363,21 @@ DecoderImpl::DecoderImpl(po::variables_map& conf, int argc, char** argv, istream ("weights,w",po::value<string>(),"Feature weights file (initial forest / pass 1)") ("feature_function,F",po::value<vector<string> >()->composing(), "Pass 1 additional feature function(s) (-L for list)") ("intersection_strategy,I",po::value<string>()->default_value("cube_pruning"), "Pass 1 intersection strategy for incorporating finite-state features; values include Cube_pruning, Full") + ("summary_feature", po::value<string>(), "Compute a 'summary feature' at the end of the pass (before any pruning) with name=arg and value=inside-outside/Z") ("density_prune", po::value<double>(), "Pass 1 pruning: keep no more than this many times the number of edges used in the best derivation tree (>=1.0)") ("beam_prune", po::value<double>(), "Pass 1 pruning: Prune paths from scored forest, keep paths within exp(alpha>=0)") ("weights2",po::value<string>(),"Optional pass 2") ("feature_function2",po::value<vector<string> >()->composing(), "Optional pass 2") ("intersection_strategy2",po::value<string>()->default_value("cube_pruning"), "Optional pass 2") + ("summary_feature2", po::value<string>(), "Optional pass 2") ("density_prune2", po::value<double>(), "Optional pass 2") ("beam_prune2", po::value<double>(), "Optional pass 2") ("weights3",po::value<string>(),"Optional pass 3") ("feature_function3",po::value<vector<string> >()->composing(), "Optional pass 3") ("intersection_strategy3",po::value<string>()->default_value("cube_pruning"), "Optional pass 3") + ("summary_feature3", po::value<string>(), "Optional pass 3") ("density_prune3", po::value<double>(), "Optional pass 3") ("beam_prune3", po::value<double>(), "Optional pass 3") @@ -559,6 +564,7 @@ DecoderImpl::DecoderImpl(po::variables_map& conf, int argc, char** argv, istream for (int pass = 0; pass < MAX_PASSES; ++pass) { string ws = "weights" + StringSuffixForRescoringPass(pass); string ff = "feature_function" + StringSuffixForRescoringPass(pass); + string sf = "summary_feature" + StringSuffixForRescoringPass(pass); string bp = "beam_prune" + StringSuffixForRescoringPass(pass); string dp = "density_prune" + StringSuffixForRescoringPass(pass); bool first_pass_condition = ((pass == 0) && (conf.count(ff) || conf.count(bp) || conf.count(dp))); @@ -583,6 +589,11 @@ DecoderImpl::DecoderImpl(po::variables_map& conf, int argc, char** argv, istream if (p->IsStateful()) { has_stateful = true; } } } + if (conf.count(sf)) { + rp.fid_summary = FD::Convert(conf[sf].as<string>()); + assert(rp.fid_summary > 0); + // TODO assert that weights for this pass have coef(fid_summary) == 0.0? + } if (conf.count(bp)) { rp.beam_prune = conf[bp].as<double>(); } if (conf.count(dp)) { rp.density_prune = conf[dp].as<double>(); } int palg = (has_stateful ? 1 : 0); // if there are no stateful featueres, default to FULL @@ -794,6 +805,47 @@ bool DecoderImpl::Decode(const string& input, DecoderObserver* o) { cerr << " " << passtr << " partition log(Z): " << log(z) << endl; } + if (rp.fid_summary) { +#if 0 + const prob_t z = forest.PushWeightsToGoal(1.0); + if (!SILENT) { cerr << " " << passtr << " adding summary feature " << FD::Convert(rp.fid_summary) << " log(Z)=" << log(z) << endl; } + if (!isfinite(log(z)) || isnan(log(z))) { + cerr << " " << passtr << " !!! Invalid partition detected, abandoning.\n"; + } else { + for (int i = 0; i < forest.edges_.size(); ++i) { + const double log_prob_transition = log(forest.edges_[i].edge_prob_); // locally normalized by the edge + // head node by forest.PushWeightsToGoal + if (!isfinite(log_prob_transition) || isnan(log_prob_transition)) { + cerr << "Edge: i=" << i << " got bad inside prob: " << *forest.edges_[i].rule_ << endl; + abort(); + } + + forest.edges_[i].feature_values_.set_value(rp.fid_summary, log_prob_transition); + } + forest.Reweight(cur_weights); // reset weights + } +#endif + Hypergraph::EdgeProbs posts; + const prob_t z = forest.ComputeEdgePosteriors(1.0, &posts); + if (!isfinite(log(z)) || isnan(log(z))) { + cerr << " " << passtr << " !!! Invalid partition detected, abandoning.\n"; + } else { + for (int i = 0; i < forest.nodes_.size(); ++i) { + const Hypergraph::EdgesVector& in_edges = forest.nodes_[i].in_edges_; + prob_t node_post = prob_t(0); + for (int j = 0; j < in_edges.size(); ++j) + node_post += (posts[in_edges[j]] / z); + const double log_np = log(node_post); + if (!isfinite(log_np) || isnan(log_np)) { + cerr << "got bad posterior prob for node " << i << endl; + abort(); + } + for (int j = 0; j < in_edges.size(); ++j) + forest.edges_[in_edges[j]].feature_values_.set_value(rp.fid_summary, exp(log_np)); + } + } + } + string fullbp = "beam_prune" + StringSuffixForRescoringPass(pass); string fulldp = "density_prune" + StringSuffixForRescoringPass(pass); maybe_prune(forest,conf,fullbp.c_str(),fulldp.c_str(),passtr,srclen); |