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
145
146
147
148
149
150
151
152
153
154
155
156
157
|
#include "ff_spans.h"
#include <sstream>
#include <cassert>
#include "filelib.h"
#include "stringlib.h"
#include "sentence_metadata.h"
#include "lattice.h"
#include "fdict.h"
#include "verbose.h"
using namespace std;
SpanFeatures::SpanFeatures(const string& param) :
kS(TD::Convert("S") * -1),
kX(TD::Convert("X") * -1),
use_collapsed_features_(false) {
string mapfile = param;
string valfile;
vector<string> toks;
Tokenize(param, ' ', &toks);
if (toks.size() == 2) { mapfile = param[0]; valfile = param[1]; }
if (mapfile.size() > 0) {
int lc = 0;
if (!SILENT) { cerr << "Reading word map for SpanFeatures from " << param << endl; }
ReadFile rf(mapfile);
istream& in = *rf.stream();
string line;
vector<WordID> v;
while(in) {
++lc;
getline(in, line);
if (line.empty()) continue;
v.clear();
TD::ConvertSentence(line, &v);
if (v.size() != 2) {
cerr << "Error reading line " << lc << ": " << line << endl;
abort();
}
word2class_[v[0]] = v[1];
}
word2class_[TD::Convert("<s>")] = TD::Convert("BOS");
word2class_[TD::Convert("</s>")] = TD::Convert("EOS");
oov_ = TD::Convert("OOV");
}
if (valfile.size() > 0) {
use_collapsed_features_ = true;
fid_beg_ = FD::Convert("SpanBegin");
fid_end_ = FD::Convert("SpanEnd");
fid_span_s_ = FD::Convert("SSpanContext");
fid_span_ = FD::Convert("XSpanContext");
ReadFile rf(valfile);
if (!SILENT) { cerr << " Loading span scores from " << valfile << endl; }
istream& in = *rf.stream();
string line;
while(in) {
getline(in, line);
if (line.size() == 0 || line[0] == '#') { continue; }
istringstream in(line);
string feat_name;
double weight;
in >> feat_name >> weight;
feat2val_[feat_name] = weight;
}
}
}
void SpanFeatures::TraversalFeaturesImpl(const SentenceMetadata& smeta,
const Hypergraph::Edge& edge,
const vector<const void*>& ant_contexts,
SparseVector<double>* features,
SparseVector<double>* estimated_features,
void* context) const {
assert(edge.j_ < end_span_ids_.size());
assert(edge.j_ >= 0);
assert(edge.i_ < beg_span_ids_.size());
assert(edge.i_ >= 0);
if (use_collapsed_features_) {
features->set_value(fid_end_, end_span_vals_[edge.j_]);
features->set_value(fid_beg_, beg_span_vals_[edge.i_]);
if (edge.rule_->lhs_ == kS)
features->set_value(fid_span_s_, span_vals_(edge.i_,edge.j_).second);
else
features->set_value(fid_span_, span_vals_(edge.i_,edge.j_).first);
} else { // non-collapsed features:
features->set_value(end_span_ids_[edge.j_], 1);
features->set_value(beg_span_ids_[edge.i_], 1);
if (edge.rule_->lhs_ == kS)
features->set_value(span_feats_(edge.i_,edge.j_).second, 1);
else
features->set_value(span_feats_(edge.i_,edge.j_).first, 1);
}
}
WordID SpanFeatures::MapIfNecessary(const WordID& w) const {
if (word2class_.empty()) return w;
map<WordID,WordID>::const_iterator it = word2class_.find(w);
if (it == word2class_.end()) return oov_;
return it->second;
}
void SpanFeatures::PrepareForInput(const SentenceMetadata& smeta) {
const Lattice& lattice = smeta.GetSourceLattice();
const WordID eos = TD::Convert("</s>");
const WordID bos = TD::Convert("<s>");
beg_span_ids_.resize(lattice.size() + 1);
end_span_ids_.resize(lattice.size() + 1);
span_feats_.resize(lattice.size() + 1, lattice.size() + 1);
if (use_collapsed_features_) {
beg_span_vals_.resize(lattice.size() + 1);
end_span_vals_.resize(lattice.size() + 1);
span_vals_.resize(lattice.size() + 1, lattice.size() + 1);
}
for (int i = 0; i <= lattice.size(); ++i) {
WordID word = eos;
WordID bword = bos;
if (i > 0)
bword = lattice[i-1][0].label;
bword = MapIfNecessary(bword);
if (i < lattice.size())
word = lattice[i][0].label; // rather arbitrary for lattices
word = MapIfNecessary(word);
ostringstream sfid;
sfid << "ES:" << TD::Convert(word);
end_span_ids_[i] = FD::Convert(sfid.str());
ostringstream bfid;
bfid << "BS:" << TD::Convert(bword);
beg_span_ids_[i] = FD::Convert(bfid.str());
if (use_collapsed_features_) {
end_span_vals_[i] = feat2val_[sfid.str()];
beg_span_vals_[i] = feat2val_[bfid.str()];
}
}
for (int i = 0; i <= lattice.size(); ++i) {
WordID bword = bos;
if (i > 0)
bword = lattice[i-1][0].label;
bword = MapIfNecessary(bword);
for (int j = 0; j <= lattice.size(); ++j) {
WordID word = eos;
if (j < lattice.size())
word = lattice[j][0].label;
word = MapIfNecessary(word);
ostringstream pf;
pf << "SS:" << TD::Convert(bword) << "_" << TD::Convert(word);
span_feats_(i,j).first = FD::Convert(pf.str());
span_feats_(i,j).second = FD::Convert("S_" + pf.str());
if (use_collapsed_features_) {
span_vals_(i,j).first = feat2val_[pf.str()];
span_vals_(i,j).second = feat2val_["S_" + pf.str()];
}
}
}
}
|
