From ea79e535d69f6854d01c62e3752971fb6730d8e7 Mon Sep 17 00:00:00 2001
From: Chris Dyer <cdyer@cs.cmu.edu>
Date: Mon, 1 Oct 2012 22:01:07 -0400
Subject: mbr fix for non-deduped lists

---
 mteval/mbr_kbest.cc | 38 ++++++++++++++++++++++++++++----------
 1 file changed, 28 insertions(+), 10 deletions(-)

(limited to 'mteval/mbr_kbest.cc')

diff --git a/mteval/mbr_kbest.cc b/mteval/mbr_kbest.cc
index 2bd31566..2519bc01 100644
--- a/mteval/mbr_kbest.cc
+++ b/mteval/mbr_kbest.cc
@@ -1,7 +1,9 @@
 #include <iostream>
 #include <vector>
+#include <tr1/unordered_map>
 
 #include <boost/program_options.hpp>
+#include <boost/functional/hash.hpp>
 
 #include "prob.h"
 #include "tdict.h"
@@ -10,6 +12,7 @@
 #include "stringlib.h"
 
 using namespace std;
+using namespace std::tr1;
 
 namespace po = boost::program_options;
 
@@ -31,27 +34,33 @@ void InitCommandLine(int argc, char** argv, po::variables_map* conf) {
   }
 }
 
+struct ScoreComparer {
+  bool operator()(const pair<vector<WordID>, prob_t>& a, const pair<vector<WordID>, prob_t>& b) const {
+    return a.second > b.second;
+  }
+};
+
 struct LossComparer {
   bool operator()(const pair<vector<WordID>, prob_t>& a, const pair<vector<WordID>, prob_t>& b) const {
     return a.second < b.second;
   }
 };
 
-bool ReadKBestList(istream* in, string* sent_id, vector<pair<vector<WordID>, prob_t> >* list) {
+bool ReadKBestList(const double mbr_scale, istream* in, string* sent_id, vector<pair<vector<WordID>, prob_t> >* list) {
   static string cache_id;
   static pair<vector<WordID>, prob_t> cache_pair;
   list->clear();
   string cur_id;
+  unordered_map<vector<WordID>, unsigned, boost::hash<vector<WordID> > > sent2id;
   if (cache_pair.first.size() > 0) {
     list->push_back(cache_pair);
+    sent2id[cache_pair.first] = 0;
     cur_id = cache_id;
     cache_pair.first.clear();
   }
   string line;
   string tstr;
-  while(*in) {
-    getline(*in, line);
-    if (line.empty()) continue;
+  while(getline(*in, line)) {
     size_t p1 = line.find(" ||| ");
     if (p1 == string::npos) { cerr << "Bad format: " << line << endl; abort(); }
     size_t p2 = line.find(" ||| ", p1 + 4);
@@ -59,16 +68,25 @@ bool ReadKBestList(istream* in, string* sent_id, vector<pair<vector<WordID>, pro
     size_t p3 = line.rfind(" ||| ");
     cache_id = line.substr(0, p1);
     tstr = line.substr(p1 + 5, p2 - p1 - 5);
-    double val = strtod(line.substr(p3 + 5).c_str(), NULL);
+    double val = strtod(line.substr(p3 + 5).c_str(), NULL) * mbr_scale;
     TD::ConvertSentence(tstr, &cache_pair.first);
     cache_pair.second.logeq(val);
     if (cur_id.empty()) cur_id = cache_id;
     if (cur_id == cache_id) {
-      list->push_back(cache_pair);
+      unordered_map<vector<WordID>, unsigned, boost::hash<vector<WordID> > >::iterator it =
+        sent2id.find(cache_pair.first);
+      if (it == sent2id.end()) {
+        sent2id.insert(make_pair(cache_pair.first, unsigned(list->size())));
+        list->push_back(cache_pair);
+      } else {
+        (*list)[it->second].second += cache_pair.second;
+        // cerr << "Cruch: " << line << "\n newp=" << (*list)[it->second].second << endl;
+      }
       *sent_id = cur_id;
       cache_pair.first.clear();
     } else { break; }
   }
+  sort(list->begin(), list->end(), ScoreComparer());
   return !list->empty();
 }
 
@@ -87,14 +105,14 @@ int main(int argc, char** argv) {
   vector<pair<vector<WordID>, prob_t> > list;
   ReadFile rf(file);
   string sent_id;
-  while(ReadKBestList(rf.stream(), &sent_id, &list)) {
+  while(ReadKBestList(mbr_scale, rf.stream(), &sent_id, &list)) {
     vector<prob_t> joints(list.size());
-    const prob_t max_score = pow(list.front().second, mbr_scale);
+    const prob_t max_score = list.front().second;
     prob_t marginal = prob_t::Zero();
     for (int i = 0 ; i < list.size(); ++i) {
-      const prob_t joint = pow(list[i].second, mbr_scale) / max_score;
+      const prob_t joint = list[i].second / max_score;
       joints[i] = joint;
-      // cerr << "list[" << i << "] joint=" << log(joint) << endl;
+      //cerr << "list[" << i << "] joint=" << log(joint) << endl;
       marginal += joint;
     }
     int mbr_idx = -1;
-- 
cgit v1.2.3