Adding backoff grammar and BackoffRule feature.

git-svn-id: https://ws10smt.googlecode.com/svn/trunk@191 ec762483-ff6d-05da-a07a-a48fb63a330f

1 files changed, 352 insertions, 0 deletions

diff --git a/extools/score_grammar.cc b/extools/score_grammar.cc
new file mode 100644
index 00000000..0945e018
--- /dev/null
+++ b/extools/score_grammar.cc
@@ -0,0 +1,352 @@
+/*
+ * Score a grammar in striped format
+ * ./score_grammar <alignment> < filtered.grammar > scored.grammar
+ */
+#include <iostream>
+#include <string>
+#include <map>
+#include <vector>
+#include <utility>
+#include <cstdlib>
+#include <fstream>
+#include <tr1/unordered_map>
+
+#include "sentence_pair.h"
+#include "extract.h"
+#include "fdict.h"
+#include "tdict.h"
+#include "lex_trans_tbl.h"
+#include "filelib.h"
+
+#include <boost/functional/hash.hpp>
+#include <boost/program_options.hpp>
+#include <boost/program_options/variables_map.hpp>
+
+using namespace std;
+using namespace std::tr1;
+
+
+static const size_t MAX_LINE_LENGTH = 64000000;
+
+typedef unordered_map<vector<WordID>, RuleStatistics, boost::hash<vector<WordID> > > ID2RuleStatistics;
+
+
+namespace {
+  inline bool IsWhitespace(char c) { return c == ' ' || c == '\t'; }
+  inline bool IsBracket(char c){return c == '[' || c == ']';}
+  inline void SkipWhitespace(const char* buf, int* ptr) {
+    while (buf[*ptr] && IsWhitespace(buf[*ptr])) { ++(*ptr); }
+  }
+}
+
+int ReadPhraseUntilDividerOrEnd(const char* buf, const int sstart, const int end, vector<WordID>* p) {
+  static const WordID kDIV = TD::Convert("|||");
+  int ptr = sstart;
+  while(ptr < end) {
+    while(ptr < end && IsWhitespace(buf[ptr])) { ++ptr; }
+    int start = ptr;
+    while(ptr < end && !IsWhitespace(buf[ptr])) { ++ptr; }
+    if (ptr == start) {cerr << "Warning! empty token.\n"; return ptr; }
+    const WordID w = TD::Convert(string(buf, start, ptr - start));
+
+    if((IsBracket(buf[start]) and IsBracket(buf[ptr-1])) or( w == kDIV))
+      p->push_back(1 * w);
+    else {
+      if (w == kDIV) return ptr;
+      p->push_back(w);
+    }
+  }
+  return ptr;
+}
+
+
+void ParseLine(const char* buf, vector<WordID>* cur_key, ID2RuleStatistics* counts) {
+  static const WordID kDIV = TD::Convert("|||");
+  counts->clear();
+  int ptr = 0;
+  while(buf[ptr] != 0 && buf[ptr] != '\t') { ++ptr; }
+  if (buf[ptr] != '\t') {
+    cerr << "Missing tab separator between key and value!\n INPUT=" << buf << endl;
+    exit(1);
+  }
+  cur_key->clear();
+  // key is: "[X] ||| word word word"
+  int tmpp = ReadPhraseUntilDividerOrEnd(buf, 0, ptr, cur_key);
+  cur_key->push_back(kDIV);
+  ReadPhraseUntilDividerOrEnd(buf, tmpp, ptr, cur_key);
+  ++ptr;
+  int start = ptr;
+  int end = ptr;
+  int state = 0; // 0=reading label, 1=reading count
+  vector<WordID> name;
+  while(buf[ptr] != 0) {
+    while(buf[ptr] != 0 && buf[ptr] != '|') { ++ptr; }
+    if (buf[ptr] == '|') {
+      ++ptr;
+      if (buf[ptr] == '|') {
+        ++ptr;
+        if (buf[ptr] == '|') {
+          ++ptr;
+          end = ptr - 3;
+          while (end > start && IsWhitespace(buf[end-1])) { --end; }
+          if (start == end) {
+            cerr << "Got empty token!\n  LINE=" << buf << endl;
+            exit(1);
+          }
+          switch (state) {
+            case 0: ++state; name.clear(); ReadPhraseUntilDividerOrEnd(buf, start, end, &name); break;
+            case 1: --state; (*counts)[name].ParseRuleStatistics(buf, start, end); break;
+            default: cerr << "Can't happen\n"; abort();
+          }
+          SkipWhitespace(buf, &ptr);
+          start = ptr;
+        }
+      }
+    }
+  }
+  end=ptr;
+  while (end > start && IsWhitespace(buf[end-1])) { --end; }
+  if (end > start) {
+    switch (state) {
+      case 0: ++state; name.clear(); ReadPhraseUntilDividerOrEnd(buf, start, end, &name); break;
+      case 1: --state; (*counts)[name].ParseRuleStatistics(buf, start, end); break;
+      default: cerr << "Can't happen\n"; abort();
+    }
+  }
+}
+
+
+
+void LexTranslationTable::createTTable(const char* buf){
+
+  bool DEBUG = false;
+
+  AnnotatedParallelSentence sent;
+      
+  sent.ParseInputLine(buf);
+      
+  //iterate over the alignment to compute aligned words
+  
+  for(int i =0;i<sent.aligned.width();i++)
+    {
+      for (int j=0;j<sent.aligned.height();j++)
+	{
+	  if (DEBUG) cerr << sent.aligned(i,j) << " ";
+	  if( sent.aligned(i,j))
+	    {
+	      if (DEBUG) cerr << TD::Convert(sent.f[i])  << " aligned to " << TD::Convert(sent.e[j]);
+	      ++word_translation[pair<WordID,WordID> (sent.f[i], sent.e[j])];
+	      ++total_foreign[sent.f[i]];
+	      ++total_english[sent.e[j]];
+	    }
+	}
+      if (DEBUG)  cerr << endl;
+    }
+  if (DEBUG) cerr << endl;
+  
+  static const WordID NULL_ = TD::Convert("NULL");
+  //handle unaligned words - align them to null
+  for (int j =0; j < sent.e_len; j++)
+    {
+      if (sent.e_aligned[j]) continue;
+      ++word_translation[pair<WordID,WordID> (NULL_, sent.e[j])];
+      ++total_foreign[NULL_];
+      ++total_english[sent.e[j]];
+    }
+  
+  for (int i =0; i < sent.f_len; i++)
+    {
+      if (sent.f_aligned[i]) continue;
+      ++word_translation[pair<WordID,WordID> (sent.f[i], NULL_)];
+      ++total_english[NULL_];
+      ++total_foreign[sent.f[i]];
+    }
+ 
+}
+
+
+inline float safenlog(float v) {
+  if (v == 1.0f) return 0.0f;
+  float res = -log(v);
+  if (res > 100.0f) res = 100.0f;
+  return res;
+}
+
+int main(int argc, char** argv){
+  bool DEBUG= false;
+  if (argc != 2) {
+    cerr << "Usage: " << argv[0] << " corpus.al < filtered.grammar\n";
+    return 1;
+  }
+  ifstream alignment (argv[1]);
+  istream& unscored_grammar = cin;
+  ostream& scored_grammar = cout;
+
+  //create lexical translation table
+  cerr << "Creating table..." << endl;
+  char* buf = new char[MAX_LINE_LENGTH];
+
+  LexTranslationTable table;
+
+  while(!alignment.eof())
+    {
+      alignment.getline(buf, MAX_LINE_LENGTH);
+      if (buf[0] == 0) continue;
+      
+      table.createTTable(buf);      	
+    }
+  
+  bool PRINT_TABLE=false;
+  if (PRINT_TABLE)
+    {
+      ofstream trans_table;
+      trans_table.open("lex_trans_table.out");
+      for(map < pair<WordID,WordID>,int >::iterator it = table.word_translation.begin(); it != table.word_translation.end(); ++it)
+      {
+	trans_table <<  TD::Convert(it->first.first) <<  "|||" << TD::Convert(it->first.second) << "==" << it->second << "//" << table.total_foreign[it->first.first] << "//" << table.total_english[it->first.second] << endl;
+      } 
+
+      trans_table.close();
+    }
+  
+ 
+  //score unscored grammar
+  cerr <<"Scoring grammar..." << endl;
+
+  ID2RuleStatistics acc, cur_counts;
+  vector<WordID> key, cur_key,temp_key;
+  vector< pair<short,short> > al;
+  vector< pair<short,short> >::iterator ita;
+  int line = 0;
+
+  static const int kCF = FD::Convert("CF");
+  static const int kCE = FD::Convert("CE");
+  static const int kCFE = FD::Convert("CFE");	
+
+  while(!unscored_grammar.eof())
+    {
+      ++line;
+      unscored_grammar.getline(buf, MAX_LINE_LENGTH);
+      if (buf[0] == 0) continue;
+      ParseLine(buf, &cur_key, &cur_counts);
+      
+      //loop over all the Target side phrases that this source aligns to
+      for (ID2RuleStatistics::const_iterator it = cur_counts.begin(); it != cur_counts.end(); ++it)
+	{
+	  
+	 /*Compute phrase translation prob.
+	   Print out scores in this format:
+	   Phrase trnaslation prob P(F|E)
+	   Phrase translation prob P(E|F)
+	   Lexical weighting prob lex(F|E)
+	   Lexical weighting prob lex(E|F)
+	 */      
+	  
+	  float pEF_ = it->second.counts.value(kCFE) / it->second.counts.value(kCF);
+	  float pFE_ = it->second.counts.value(kCFE) / it->second.counts.value(kCE);
+
+	  map <WordID, pair<int, float> > foreign_aligned;
+	  map <WordID, pair<int, float> > english_aligned;
+
+	  //Loop over all the alignment points to compute lexical translation probability
+	  al = it->second.aligns;	  
+	  for(ita = al.begin(); ita != al.end(); ++ita)
+	    {
+	     
+	      if (DEBUG)
+		{
+		  cerr << "\nA:" << ita->first << "," << ita->second << "::";
+		  cerr <<  TD::Convert(cur_key[ita->first + 2]) << "-" << TD::Convert(it->first[ita->second]);
+		}
+
+
+	      //Lookup this alignment probability in the table
+	      int temp = table.word_translation[pair<WordID,WordID> (cur_key[ita->first+2],it->first[ita->second])];
+	      float f2e=0, e2f=0;
+	      if ( table.total_foreign[cur_key[ita->first+2]] != 0)
+		f2e = (float) temp / table.total_foreign[cur_key[ita->first+2]];
+	      if ( table.total_english[it->first[ita->second]] !=0 )
+		e2f = (float) temp / table.total_english[it->first[ita->second]];
+	      if (DEBUG) printf (" %d %E %E\n", temp, f2e, e2f);
+	      
+	      
+	      //local counts to keep track of which things haven't been aligned, to later compute their null alignment	      
+	      if (foreign_aligned.count(cur_key[ita->first+2]))
+		{
+		  foreign_aligned[ cur_key[ita->first+2] ].first++;
+		  foreign_aligned[ cur_key[ita->first+2] ].second += e2f;
+		}
+	      else
+		foreign_aligned [ cur_key[ita->first+2] ] = pair<int,float> (1,e2f);
+		
+	      
+
+	      if (english_aligned.count( it->first[ ita->second] ))
+		{
+		  english_aligned[ it->first[ ita->second ]].first++;
+		  english_aligned[  it->first[ ita->second] ].second += f2e;
+		}
+	      else
+		english_aligned [ it->first[ ita->second] ] = pair<int,float> (1,f2e);
+		
+	      
+	    
+	   	      
+	    }
+
+	  float final_lex_f2e=1, final_lex_e2f=1;
+	  static const WordID NULL_ = TD::Convert("NULL");
+
+	  //compute lexical weight P(F|E) and include unaligned foreign words
+	   for(int i=0;i<cur_key.size(); i++)
+	     {
+	       
+	       if (!table.total_foreign.count(cur_key[i])) continue;      //if we dont have it in the translation table, we won't know its lexical weight
+	       
+	       if (foreign_aligned.count(cur_key[i])) 
+		 {
+		   pair<int, float> temp_lex_prob = foreign_aligned[cur_key[i]];
+		   final_lex_e2f *= temp_lex_prob.second / temp_lex_prob.first;
+		 }
+	       else //dealing with null alignment
+		 {
+		   int temp_count = table.word_translation[pair<WordID,WordID> (cur_key[i],NULL_)];
+		   float temp_e2f = (float) temp_count / table.total_english[NULL_];
+		   final_lex_e2f *= temp_e2f;
+		 }	       	       
+
+	     }
+
+	   //compute P(E|F) unaligned english words
+	   for(int j=0; j< it->first.size(); j++)
+	     {
+	       if (!table.total_english.count(it->first[j])) continue;
+	       
+	       if (english_aligned.count(it->first[j]))
+		 {
+		   pair<int, float> temp_lex_prob = english_aligned[it->first[j]];
+		   final_lex_f2e *= temp_lex_prob.second / temp_lex_prob.first;
+		 }
+	       else //dealing with null
+		 {
+		   int temp_count = table.word_translation[pair<WordID,WordID> (NULL_,it->first[j])];
+		   float temp_f2e = (float) temp_count / table.total_foreign[NULL_];
+		   final_lex_f2e *= temp_f2e;
+		 }
+	     }
+	   
+	   
+       scored_grammar << TD::GetString(cur_key);
+       string lhs = TD::Convert(cur_key[0]);
+	   scored_grammar << " " << TD::GetString(it->first) << " |||";
+	   if(lhs.find('_')!=string::npos) {
+	       scored_grammar << " Bkoff=" << safenlog(3.0f);
+	   } else {
+	       scored_grammar << " FGivenE=" << safenlog(pFE_) << " EGivenF=" << safenlog(pEF_);
+	       scored_grammar << " LexE2F=" << safenlog(final_lex_e2f) << " LexF2E=" << safenlog(final_lex_f2e);
+	   }  
+	   scored_grammar << endl;
+	}  
+    }
+}
+