rule shape features

git-svn-id: https://ws10smt.googlecode.com/svn/trunk@46 ec762483-ff6d-05da-a07a-a48fb63a330f

1 files changed, 104 insertions, 0 deletions

diff --git a/decoder/ff_ruleshape.cc b/decoder/ff_ruleshape.cc
new file mode 100644
index 00000000..d473704a
--- /dev/null
+++ b/decoder/ff_ruleshape.cc
@@ -0,0 +1,104 @@
+#include "ff_ruleshape.h"
+
+#include "fdict.h"
+#include <sstream>
+
+using namespace std;
+
+inline bool IsBitSet(int i, int bit) {
+  const int mask = 1 << bit;
+  return (i & mask);
+}
+
+inline char BitAsChar(bool bit) {
+  return (bit ? '1' : '0');
+}
+
+RuleShapeFeatures::RuleShapeFeatures(const string& param) {
+  bool first = true;
+  for (int i = 0; i < 32; ++i) {
+    for (int j = 0; j < 32; ++j) {
+      ostringstream os;
+      os << "Shape_S";
+      Node* cur = &fidtree_;
+      for (int k = 0; k < 5; ++k) {
+        bool bit = IsBitSet(i,k);
+        cur = &cur->next_[bit];
+        os << BitAsChar(bit);
+      }
+      os << "_T"; 
+      for (int k = 0; k < 5; ++k) {
+        bool bit = IsBitSet(j,k);
+        cur = &cur->next_[bit];
+        os << BitAsChar(bit);
+      }
+      if (first) { first = false; cerr << "  Example feature: " << os.str() << endl; }
+      cur->fid_ = FD::Convert(os.str());
+    }
+  }
+}
+
+void RuleShapeFeatures::TraversalFeaturesImpl(const SentenceMetadata& smeta,
+                                              const Hypergraph::Edge& edge,
+                                              const vector<const void*>& ant_contexts,
+                                              SparseVector<double>* features,
+                                              SparseVector<double>* estimated_features,
+                                              void* context) const {
+  const Node* cur = &fidtree_;
+  TRule& rule = *edge.rule_;
+  int pos = 0;  // feature position
+  int i = 0;
+  while(i < rule.f_.size()) {
+    WordID sym = rule.f_[i];
+    if (pos % 2 == 0) {
+      if (sym > 0) {       // is terminal
+        cur = Advance(cur, true);
+        while (i < rule.f_.size() && rule.f_[i] > 0) ++i;  // consume lexical string
+      } else {
+        cur = Advance(cur, false);
+      }
+      ++pos;
+    } else {  // expecting a NT
+      if (sym < 1) {
+        cur = Advance(cur, true);
+        ++i;
+        ++pos;
+      } else {
+        cerr << "BAD RULE: " << rule.AsString() << endl;
+        exit(1);
+      }
+    }
+  }
+  for (; pos < 5; ++pos)
+    cur = Advance(cur, false);
+  assert(pos == 5);  // this will fail if you are using using > binary rules!
+
+  i = 0;
+  while(i < rule.e_.size()) {
+    WordID sym = rule.e_[i];
+    if (pos % 2 == 1) {
+      if (sym > 0) {       // is terminal
+        cur = Advance(cur, true);
+        while (i < rule.e_.size() && rule.e_[i] > 0) ++i;  // consume lexical string
+      } else {
+        cur = Advance(cur, false);
+      }
+      ++pos;
+    } else {  // expecting a NT
+      if (sym < 1) {
+        cur = Advance(cur, true);
+        ++i;
+        ++pos;
+      } else {
+        cerr << "BAD RULE: " << rule.AsString() << endl;
+        exit(1);
+      }
+    }
+  }
+  for (;pos < 10; ++pos)
+    cur = Advance(cur, false);
+  assert(pos == 10);  // this will fail if you are using using > binary rules!
+
+  features->set_value(cur->fid_, 1.0);
+}
+