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-rw-r--r--dtrain/score.cc132
1 files changed, 69 insertions, 63 deletions
diff --git a/dtrain/score.cc b/dtrain/score.cc
index 52644250..9b22508b 100644
--- a/dtrain/score.cc
+++ b/dtrain/score.cc
@@ -4,40 +4,6 @@ namespace dtrain
{
-Ngrams
-make_ngrams(vector<WordID>& s, 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;
-}
-
-NgramCounts
-make_ngram_counts(vector<WordID> hyp, vector<WordID> ref, 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;
-}
-
/*
* bleu
*
@@ -48,26 +14,28 @@ make_ngram_counts(vector<WordID> hyp, vector<WordID> ref, unsigned N)
* NOTE: 0 if one n in {1..N} has 0 count
*/
score_t
-brevity_penaly(const unsigned hyp_len, const unsigned ref_len)
-{
- if (hyp_len > ref_len) return 1;
- return exp(1 - (score_t)ref_len/hyp_len);
-}
-score_t
-bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
- unsigned N, vector<score_t> weights )
+BleuScorer::Bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len)
{
if (hyp_len == 0 || ref_len == 0) return 0;
- if (ref_len < N) N = ref_len;
- if (weights.empty()) for (unsigned i = 0; i < N; i++) weights.push_back(1./N);
+ unsigned M = N_;
+ if (ref_len < N_) M = ref_len;
score_t sum = 0;
- for (unsigned i = 0; i < N; i++) {
+ for (unsigned i = 0; i < M; i++) {
if (counts.clipped[i] == 0 || counts.sum[i] == 0) return 0;
- sum += weights[i] * log((score_t)counts.clipped[i] / counts.sum[i]);
+ sum += w_[i] * log((score_t)counts.clipped[i] / counts.sum[i]);
}
return brevity_penaly(hyp_len, ref_len) * exp(sum);
}
+score_t
+BleuScorer::Score(ScoredHyp& hyp, vector<WordID>& ref_ids, unsigned id)
+{
+ unsigned hyp_len = hyp.w.size(), ref_len = ref_ids.size();
+ if (hyp_len == 0 || ref_len == 0) return 0;
+ NgramCounts counts = make_ngram_counts(hyp.w, ref_ids, N_);
+ return Bleu(counts, hyp_len, ref_len);
+}
+
/*
* 'stupid' bleu
*
@@ -79,18 +47,31 @@ bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
* NOTE: 0 iff no 1gram match
*/
score_t
-stupid_bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
- unsigned N, vector<score_t> weights )
+StupidBleuScorer::Score(ScoredHyp& hyp, vector<WordID>& ref_ids, unsigned id)
{
+ unsigned hyp_len = hyp.w.size(), ref_len = ref_ids.size();
if (hyp_len == 0 || ref_len == 0) return 0;
- if (ref_len < N) N = ref_len;
- if (weights.empty()) for (unsigned i = 0; i < N; i++) weights.push_back(1./N);
+ NgramCounts counts = make_ngram_counts(hyp.w, ref_ids, N_);
+ unsigned M = N_;
+ if (ref_len < N_) M = ref_len;
score_t sum = 0, add = 0;
- for (unsigned i = 0; i < N; i++) {
+ for (unsigned i = 0; i < M; i++) {
if (i == 1) add = 1;
- sum += weights[i] * log(((score_t)counts.clipped[i] + add) / ((counts.sum[i] + add)));
+ //cout << ((score_t)counts.clipped[i] + add) << "/" << counts.sum[i] +add << "." << endl;
+ //cout << "w_[i] " << w_[i] << endl;
+ sum += w_[i] * log(((score_t)counts.clipped[i] + add) / ((counts.sum[i] + add)));
+ //cout << "sum += "<< w_[i] * log(((score_t)counts.clipped[i] + add) / ((counts.sum[i] + add))) << endl;
}
- return brevity_penaly(hyp_len, ref_len) * exp(sum);
+ /*cout << ref_ids << endl;
+ cout << hyp.w << endl;
+ cout << "ref_len " << ref_len << endl;
+ cout << "hyp_len " << hyp_len << endl;
+ cout << "bp " << brevity_penaly(hyp_len, ref_len) << endl;
+ cout << "exp(sum) " << exp(sum) << endl;
+ counts.Print();
+ cout << brevity_penaly(hyp_len, ref_len) * exp(sum) << endl;
+ cout << "---" << endl;*/
+ return brevity_penaly(hyp_len, ref_len) * exp(sum);
}
/*
@@ -103,16 +84,16 @@ stupid_bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
* NOTE: max is 0.9375
*/
score_t
-smooth_bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
- const unsigned N, vector<score_t> weights )
+SmoothBleuScorer::Score(ScoredHyp& hyp, vector<WordID>& ref_ids, unsigned id)
{
+ unsigned hyp_len = hyp.w.size(), ref_len = ref_ids.size();
if (hyp_len == 0 || ref_len == 0) return 0;
- if (weights.empty()) for (unsigned i = 0; i < N; i++) weights.push_back(1./N);
+ NgramCounts counts = make_ngram_counts(hyp.w, ref_ids, N_);
score_t sum = 0;
unsigned j = 1;
- for (unsigned i = 0; i < N; i++) {
+ for (unsigned i = 0; i < N_; i++) {
if (counts.clipped[i] == 0 || counts.sum[i] == 0) continue;
- sum += exp((weights[i] * log((score_t)counts.clipped[i]/counts.sum[i]))) / pow(2, N-j+1);
+ sum += exp((w_[i] * log((score_t)counts.clipped[i]/counts.sum[i]))) / pow(2, N_-j+1);
j++;
}
return brevity_penaly(hyp_len, ref_len) * sum;
@@ -125,14 +106,39 @@ smooth_bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
* and Structural Translation Features"
* (Chiang et al. '08)
*/
-score_t
-approx_bleu(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len,
- const unsigned N, vector<score_t> weights)
+/*void
+ApproxBleuScorer::Prep(NgramCounts& counts, const unsigned hyp_len, const unsigned ref_len)
+{
+ glob_onebest_counts += counts;
+ glob_hyp_len += hyp_len;
+ glob_ref_len += ref_len;
+}
+
+void
+ApproxBleuScorer::Reset()
{
- return brevity_penaly(hyp_len, ref_len)
- * 0.9 * bleu(counts, hyp_len, ref_len, N, weights);
+ glob_onebest_counts.Zero();
+ glob_hyp_len = 0;
+ glob_ref_len = 0;
}
+score_t
+ApproxBleuScorer::Score(ScoredHyp& hyp, vector<WordID>& ref_ids, unsigned id)
+{
+ NgramCounts counts = make_ngram_counts(hyp.w, ref_ids, N_);
+ if (id == 0) reset();
+ unsigned hyp_len = 0, ref_len = 0;
+ if (hyp.rank == 0) { // 'context of 1best translations'
+ scorer->prep(counts, hyp.w.size(), ref_ids.size());
+ counts.reset();
+ } else {
+ hyp_len = hyp.w.size();
+ ref_len = ref_ids.size();
+ }
+ return 0.9 * BleuScorer::Bleu(glob_onebest_counts + counts,
+ glob_hyp_len + hyp_len, glob_ref_len + ref_len);
+}*/
+
} // namespace
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-11 19:50:14 +0000