1 files changed, 37 insertions, 0 deletions
diff --git a/extractor/features/max_lex_source_given_target.cc b/extractor/features/max_lex_source_given_target.cc
new file mode 100644
index 00000000..65d0ec68
--- /dev/null
+++ b/extractor/features/max_lex_source_given_target.cc
@@ -0,0 +1,37 @@
+#include "max_lex_source_given_target.h"
+
+#include <cmath>
+
+#include "data_array.h"
+#include "translation_table.h"
+
+namespace extractor {
+namespace features {
+
+MaxLexSourceGivenTarget::MaxLexSourceGivenTarget(
+    shared_ptr<TranslationTable> table) :
+    table(table) {}
+
+double MaxLexSourceGivenTarget::Score(const FeatureContext& context) const {
+  vector<string> source_words = context.source_phrase.GetWords();
+  vector<string> target_words = context.target_phrase.GetWords();
+  target_words.push_back(DataArray::NULL_WORD_STR);
+
+  double score = 0;
+  for (string source_word: source_words) {
+    double max_score = 0;
+    for (string target_word: target_words) {
+      max_score = max(max_score,
+          table->GetSourceGivenTargetScore(source_word, target_word));
+    }
+    score += max_score > 0 ? -log10(max_score) : MAX_SCORE;
+  }
+  return score;
+}
+
+string MaxLexSourceGivenTarget::GetName() const {
+  return "MaxLexFgivenE";
+}
+
+} // namespace features
+} // namespace extractor