summaryrefslogtreecommitdiff
path: root/dtrain/score.h
blob: 5aceb81fce5e2fdbe9690c2df54e9fd2fa44a306 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
#ifndef _DTRAIN_SCORE_H_
#define _DTRAIN_SCORE_H_

#include "kbestget.h"

using namespace std;

namespace dtrain
{


struct NgramCounts
{
  unsigned N_;
  map<unsigned, unsigned> clipped;
  map<unsigned, unsigned> sum;

  NgramCounts(const unsigned N) : N_(N) { Zero(); }

  inline void
  operator+=(const NgramCounts& rhs)
  {
    assert(N_ == rhs.N_);
    for (unsigned i = 0; i < N_; i++) {
      this->clipped[i] += rhs.clipped.find(i)->second;
      this->sum[i] += rhs.sum.find(i)->second;
    }
  }

  inline const NgramCounts
  operator+(const NgramCounts &other) const
  {
    NgramCounts result = *this;
    result += other;
    return result;
  }

  inline void
  Add(const unsigned count, const unsigned ref_count, const unsigned i)
  {
    assert(i < N_);
    if (count > ref_count) {
      clipped[i] += ref_count;
    } else {
      clipped[i] += count;
    }
    sum[i] += count;
  }

  inline void
  Zero()
  {
    unsigned i;
    for (i = 0; i < N_; i++) {
      clipped[i] = 0;
      sum[i] = 0;
    }
  }

  inline void
  Print()
  {
    for (unsigned i = 0; i < N_; i++) {
      cout << i+1 << "grams (clipped):\t" << clipped[i] << endl;
      cout << i+1 << "grams:\t\t\t" << sum[i] << endl;
    }
  }
};

typedef map<vector<WordID>, unsigned> Ngrams;

inline Ngrams
make_ngrams(const vector<WordID>& s, const unsigned N)
{
  Ngrams ngrams;
  vector<WordID> ng;
  for (size_t i = 0; i < s.size(); i++) {
    ng.clear();
    for (unsigned j = i; j < min(i+N, s.size()); j++) {
      ng.push_back(s[j]);
      ngrams[ng]++;
    }
  }
  return ngrams;
}

inline NgramCounts
make_ngram_counts(const vector<WordID>& hyp, const vector<WordID>& ref, const unsigned N)
{
  Ngrams hyp_ngrams = make_ngrams(hyp, N);
  Ngrams ref_ngrams = make_ngrams(ref, N);
  NgramCounts counts(N);
  Ngrams::iterator it;
  Ngrams::iterator ti;
  for (it = hyp_ngrams.begin(); it != hyp_ngrams.end(); it++) {
    ti = ref_ngrams.find(it->first);
    if (ti != ref_ngrams.end()) {
      counts.Add(it->second, ti->second, it->first.size() - 1);
    } else {
      counts.Add(it->second, 0, it->first.size() - 1);
    }
  }
  return counts;
}

struct BleuScorer : public LocalScorer
{
  score_t Bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len);
  score_t Score(vector<WordID>& hyp, vector<WordID>& ref, const unsigned rank);
};

struct StupidBleuScorer : public LocalScorer
{
  score_t Score(vector<WordID>& hyp, vector<WordID>& ref, const unsigned rank);
};

struct SmoothBleuScorer : public LocalScorer
{
  score_t Score(vector<WordID>& hyp, vector<WordID>& ref, const unsigned rank);
};

struct ApproxBleuScorer : public BleuScorer
{
  NgramCounts glob_onebest_counts;
  unsigned glob_hyp_len, glob_ref_len;

  ApproxBleuScorer(unsigned N) : glob_onebest_counts(NgramCounts(N))
  {
    glob_hyp_len = glob_ref_len = 0;
  }

  inline void Reset() {
    glob_onebest_counts.Zero();
    glob_hyp_len = glob_ref_len = 0;
  }

  score_t Score(vector<WordID>& hyp, vector<WordID>& ref, const unsigned rank);
};


} // namespace

#endif