2 files changed, 99 insertions, 0 deletions
diff --git a/vest/ces.cc b/vest/ces.cc
new file mode 100644
index 00000000..aa341058
--- /dev/null
+++ b/vest/ces.cc
@@ -0,0 +1,87 @@
+#include "ces.h"
+
+#include <vector>
+#include <sstream>
+#include <boost/shared_ptr.hpp>
+
+#include "aligner.h"
+#include "lattice.h"
+#include "viterbi_envelope.h"
+#include "error_surface.h"
+
+using boost::shared_ptr;
+using namespace std;
+
+const bool minimize_segments = true;    // if adjacent segments have equal scores, merge them
+
+void ComputeErrorSurface(const SentenceScorer& ss, const ViterbiEnvelope& ve, ErrorSurface* env, const ScoreType type, const Hypergraph& hg) {
+  vector<WordID> prev_trans;
+  const vector<shared_ptr<Segment> >& ienv = ve.GetSortedSegs();
+  env->resize(ienv.size());
+  ScoreP prev_score;
+  int j = 0;
+  for (int i = 0; i < ienv.size(); ++i) {
+    const Segment& seg = *ienv[i];
+    vector<WordID> trans;
+    if (type == AER) {
+      vector<bool> edges(hg.edges_.size(), false);
+      seg.CollectEdgesUsed(&edges);  // get the set of edges in the viterbi
+                                     // alignment
+      ostringstream os;
+      const string* psrc = ss.GetSource();
+      if (psrc == NULL) {
+        cerr << "AER scoring in VEST requires source, but it is missing!\n";
+        abort();
+      }
+      size_t pos = psrc->rfind(" ||| ");
+      if (pos == string::npos) {
+        cerr << "Malformed source for AER: expected |||\nINPUT: " << *psrc << endl;
+        abort();
+      }
+      Lattice src;
+      Lattice ref;
+      LatticeTools::ConvertTextOrPLF(psrc->substr(0, pos), &src);
+      LatticeTools::ConvertTextOrPLF(psrc->substr(pos + 5), &ref);
+      AlignerTools::WriteAlignment(src, ref, hg, &os, true, &edges);
+      string tstr = os.str();
+      TD::ConvertSentence(tstr.substr(tstr.rfind(" ||| ") + 5), &trans);
+    } else {
+      seg.ConstructTranslation(&trans);
+    }
+    // cerr << "Scoring: " << TD::GetString(trans) << endl;
+    if (trans == prev_trans) {
+      if (!minimize_segments) {
+        assert(prev_score); // if this fails, it means
+	                    // the decoder can generate null translations
+        ErrorSegment& out = (*env)[j];
+        out.delta = prev_score->GetZero();
+        out.x = seg.x;
+	++j;
+      }
+      // cerr << "Identical translation, skipping scoring\n";
+    } else {
+      ScoreP score = ss.ScoreCandidate(trans);
+      // cerr << "score= " << score->ComputeScore() << "\n";
+      ScoreP cur_delta_p = score->GetZero();
+      Score* cur_delta = cur_delta_p.get();
+      // just record the score diffs
+      if (!prev_score)
+        prev_score = score->GetZero();
+
+      score->Subtract(*prev_score, cur_delta);
+      prev_trans.swap(trans);
+      prev_score = score;
+      if ((!minimize_segments) || (!cur_delta->IsAdditiveIdentity())) {
+        ErrorSegment& out = (*env)[j];
+        out.delta = cur_delta_p;
+        out.x = seg.x;
+        ++j;
+      }
+    }
+  }
+  // cerr << " In segments: " << ienv.size() << endl;
+  // cerr << "Out segments: " << j << endl;
+  assert(j > 0);
+  env->resize(j);
+}
+
diff --git a/vest/ces.h b/vest/ces.h
new file mode 100644
index 00000000..2f098990
--- /dev/null
+++ b/vest/ces.h
@@ -0,0 +1,12 @@
+#ifndef _CES_H_
+#define _CES_H_
+
+#include "scorer.h"
+
+class ViterbiEnvelope;
+class Hypergraph;
+class ErrorSurface;
+
+void ComputeErrorSurface(const SentenceScorer& ss, const ViterbiEnvelope& ve, ErrorSurface* es, const ScoreType type, const Hypergraph& hg);
+
+#endif