summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorChris Dyer <cdyer@cs.cmu.edu>2011-03-22 14:44:46 -0400
committerChris Dyer <cdyer@cs.cmu.edu>2011-03-22 14:44:46 -0400
commitc0ae6f362b245ccf2ab3b8d6dc7e367cbcc64c1c (patch)
tree1f24d437285147f08d8dd868dc1cb217e208c931
parent4bc9ea17ba9f85c899e35a9d657ee3f174ff2863 (diff)
fix local normalizer code for summary features
-rw-r--r--decoder/decoder.cc16
-rw-r--r--decoder/hg.cc5
-rw-r--r--decoder/hg.h2
3 files changed, 15 insertions, 8 deletions
diff --git a/decoder/decoder.cc b/decoder/decoder.cc
index a16a9b5a..89425198 100644
--- a/decoder/decoder.cc
+++ b/decoder/decoder.cc
@@ -806,15 +806,21 @@ bool DecoderImpl::Decode(const string& input, DecoderObserver* o) {
}
if (rp.fid_summary) {
- Hypergraph::EdgeProbs posteriors;
- const prob_t z = forest.ComputeEdgePosteriors(1.0, &posteriors);
+ 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; }
- assert(forest.edges_.size() == posteriors.size());
if (!isfinite(log(z)) || isnan(log(z))) {
cerr << " " << passtr << " !!! Invalid partition detected, abandoning.\n";
} else {
- for (int i = 0; i < posteriors.size(); ++i)
- forest.edges_[i].feature_values_.set_value(rp.fid_summary, log(posteriors[i] / z));
+ 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);
+ }
}
}
diff --git a/decoder/hg.cc b/decoder/hg.cc
index 39ac5132..a4028b0e 100644
--- a/decoder/hg.cc
+++ b/decoder/hg.cc
@@ -226,9 +226,9 @@ prob_t Hypergraph::PushViterbiWeightsToGoal(int fid) {
}
-void Hypergraph::PushWeightsToGoal(double scale) {
+prob_t Hypergraph::PushWeightsToGoal(double scale) {
vector<prob_t> posts;
- ComputeEdgePosteriors(scale, &posts);
+ const prob_t inside_z = ComputeEdgePosteriors(scale, &posts);
for (int i = 0; i < nodes_.size(); ++i) {
const Hypergraph::Node& node = nodes_[i];
prob_t z = prob_t::Zero();
@@ -238,6 +238,7 @@ void Hypergraph::PushWeightsToGoal(double scale) {
edges_[node.in_edges_[j]].edge_prob_ = posts[node.in_edges_[j]] / z;
}
}
+ return inside_z;
}
struct EdgeExistsWeightFunction {
diff --git a/decoder/hg.h b/decoder/hg.h
index aa1202b1..e5ef05f8 100644
--- a/decoder/hg.h
+++ b/decoder/hg.h
@@ -449,7 +449,7 @@ public:
void PushWeightsToSource(double scale = 1.0);
// same, except weights are pushed to the goal, works for HGs,
// not just lattices
- void PushWeightsToGoal(double scale = 1.0);
+ prob_t PushWeightsToGoal(double scale = 1.0);
// contrary to PushWeightsToGoal, use viterbi semiring; store log(p) to fid. note that p_viterbi becomes 1; k*p_viterbi becomes k. also modifies edge_prob_ (note that the fid stored log(p) will stick around even if you reweight)
// afterwards, product of edge_prob_ for a derivation will equal 1 for the viterbi (p_v before, 1 after), and in general (k*p_v before, k after). returns inside(goal)