compute held-out ppl in mpi_batch_optimize

1 files changed, 52 insertions, 0 deletions

diff --git a/training/cllh_observer.cc b/training/cllh_observer.cc
new file mode 100644
index 00000000..58232769
--- /dev/null
+++ b/training/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(!isnan(log_ref_z));
+  acc_obj += (cur_obj - log_ref_z);
+  trg_words += smeta.GetReference().size();
+}
+