From 1b8181bf0d6e9137e6b9ccdbe414aec37377a1a9 Mon Sep 17 00:00:00 2001
From: Chris Dyer <cdyer@allegro.clab.cs.cmu.edu>
Date: Sun, 18 Nov 2012 13:35:42 -0500
Subject: major restructure of the training code

---
 training/crf/cllh_observer.cc | 52 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
 create mode 100644 training/crf/cllh_observer.cc

(limited to 'training/crf/cllh_observer.cc')

diff --git a/training/crf/cllh_observer.cc b/training/crf/cllh_observer.cc
new file mode 100644
index 00000000..4ec2fa65
--- /dev/null
+++ b/training/crf/cllh_observer.cc
@@ -0,0 +1,52 @@
+#include "cllh_observer.h"
+
+#include <cmath>
+#include <cassert>
+
+#include "inside_outside.h"
+#include "hg.h"
+#include "sentence_metadata.h"
+
+using namespace std;
+
+static const double kMINUS_EPSILON = -1e-6;
+
+ConditionalLikelihoodObserver::~ConditionalLikelihoodObserver() {}
+
+void ConditionalLikelihoodObserver::NotifyDecodingStart(const SentenceMetadata&) {
+  cur_obj = 0;
+  state = 1;
+}
+
+void ConditionalLikelihoodObserver::NotifyTranslationForest(const SentenceMetadata&, Hypergraph* hg) {
+  assert(state == 1);
+  state = 2;
+  SparseVector<prob_t> cur_model_exp;
+  const prob_t z = InsideOutside<prob_t,
+                                 EdgeProb,
+                                 SparseVector<prob_t>,
+                                 EdgeFeaturesAndProbWeightFunction>(*hg, &cur_model_exp);
+  cur_obj = log(z);
+}
+
+void ConditionalLikelihoodObserver::NotifyAlignmentForest(const SentenceMetadata& smeta, Hypergraph* hg) {
+  assert(state == 2);
+  state = 3;
+  SparseVector<prob_t> ref_exp;
+  const prob_t ref_z = InsideOutside<prob_t,
+                                     EdgeProb,
+                                     SparseVector<prob_t>,
+                                     EdgeFeaturesAndProbWeightFunction>(*hg, &ref_exp);
+
+  double log_ref_z = log(ref_z);
+
+  // rounding errors means that <0 is too strict
+  if ((cur_obj - log_ref_z) < kMINUS_EPSILON) {
+    cerr << "DIFF. ERR! log_model_z < log_ref_z: " << cur_obj << " " << log_ref_z << endl;
+    exit(1);
+  }
+  assert(!std::isnan(log_ref_z));
+  acc_obj += (cur_obj - log_ref_z);
+  trg_words += smeta.GetReference().size();
+}
+
-- 
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