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
|
#include "translation_table.h"
#include <string>
#include <vector>
#include <boost/functional/hash.hpp>
#include "alignment.h"
#include "data_array.h"
using namespace std;
namespace extractor {
TranslationTable::TranslationTable(shared_ptr<DataArray> source_data_array,
shared_ptr<DataArray> target_data_array,
shared_ptr<Alignment> alignment) :
source_data_array(source_data_array), target_data_array(target_data_array) {
const vector<int>& source_data = source_data_array->GetData();
const vector<int>& target_data = target_data_array->GetData();
unordered_map<int, int> source_links_count;
unordered_map<int, int> target_links_count;
unordered_map<pair<int, int>, int, PairHash> links_count;
for (size_t i = 0; i < source_data_array->GetNumSentences(); ++i) {
vector<pair<int, int> > links = alignment->GetLinks(i);
int source_start = source_data_array->GetSentenceStart(i);
int target_start = target_data_array->GetSentenceStart(i);
// Ignore END_OF_LINE markers.
int next_source_start = source_data_array->GetSentenceStart(i + 1) - 1;
int next_target_start = target_data_array->GetSentenceStart(i + 1) - 1;
vector<int> source_sentence(source_data.begin() + source_start,
source_data.begin() + next_source_start);
vector<int> target_sentence(target_data.begin() + target_start,
target_data.begin() + next_target_start);
vector<int> source_linked_words(source_sentence.size());
vector<int> target_linked_words(target_sentence.size());
for (pair<int, int> link: links) {
source_linked_words[link.first] = 1;
target_linked_words[link.second] = 1;
IncreaseLinksCount(source_links_count, target_links_count, links_count,
source_sentence[link.first], target_sentence[link.second]);
}
for (size_t i = 0; i < source_sentence.size(); ++i) {
if (!source_linked_words[i]) {
IncreaseLinksCount(source_links_count, target_links_count, links_count,
source_sentence[i], DataArray::NULL_WORD);
}
}
for (size_t i = 0; i < target_sentence.size(); ++i) {
if (!target_linked_words[i]) {
IncreaseLinksCount(source_links_count, target_links_count, links_count,
DataArray::NULL_WORD, target_sentence[i]);
}
}
}
for (pair<pair<int, int>, int> link_count: links_count) {
int source_word = link_count.first.first;
int target_word = link_count.first.second;
double score1 = 1.0 * link_count.second / source_links_count[source_word];
double score2 = 1.0 * link_count.second / target_links_count[target_word];
translation_probabilities[link_count.first] = make_pair(score1, score2);
}
}
TranslationTable::TranslationTable() {}
TranslationTable::~TranslationTable() {}
void TranslationTable::IncreaseLinksCount(
unordered_map<int, int>& source_links_count,
unordered_map<int, int>& target_links_count,
unordered_map<pair<int, int>, int, PairHash>& links_count,
int source_word_id,
int target_word_id) const {
++source_links_count[source_word_id];
++target_links_count[target_word_id];
++links_count[make_pair(source_word_id, target_word_id)];
}
double TranslationTable::GetTargetGivenSourceScore(
const string& source_word, const string& target_word) {
if (!source_data_array->HasWord(source_word) ||
!target_data_array->HasWord(target_word)) {
return -1;
}
int source_id = source_data_array->GetWordId(source_word);
int target_id = target_data_array->GetWordId(target_word);
return translation_probabilities[make_pair(source_id, target_id)].first;
}
double TranslationTable::GetSourceGivenTargetScore(
const string& source_word, const string& target_word) {
if (!source_data_array->HasWord(source_word) ||
!target_data_array->HasWord(target_word)) {
return -1;
}
int source_id = source_data_array->GetWordId(source_word);
int target_id = target_data_array->GetWordId(target_word);
return translation_probabilities[make_pair(source_id, target_id)].second;
}
void TranslationTable::WriteBinary(const fs::path& filepath) const {
FILE* file = fopen(filepath.string().c_str(), "w");
int size = translation_probabilities.size();
fwrite(&size, sizeof(int), 1, file);
for (auto entry: translation_probabilities) {
fwrite(&entry.first, sizeof(entry.first), 1, file);
fwrite(&entry.second, sizeof(entry.second), 1, file);
}
}
} // namespace extractor
|
