am 7557d3c6: am bc77adef: Merge "Return the bigram frequency if available." into jb-dev

* commit '7557d3c6f3e7669fa213dbabda0f399e496b56b7':
  Return the bigram frequency if available.
main
Jean Chalard 2012-05-21 11:52:23 -07:00 committed by Android Git Automerger
commit 239401745b
3 changed files with 28 additions and 13 deletions

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@ -75,9 +75,9 @@
<item></item>
<!-- Modest : Suggestion whose normalized score is greater than this value
will be subject to auto-correction. -->
<item>0.22</item>
<item>0.185</item>
<!-- Aggressive -->
<item>0.08</item>
<item>0.067</item>
<!-- Very Aggressive : Suggestion whose normalized score is greater than this value
will be subject to auto-correction. -->
<item>0</item>

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@ -520,19 +520,33 @@ inline int BinaryFormat::getWordAtAddress(const uint8_t* const root, const int a
return 0;
}
// This should probably return a probability in log space.
static inline int backoff(const int unigramFreq) {
return unigramFreq;
// For some reason, applying the backoff weight gives bad results in tests. To apply the
// backoff weight, we divide the probability by 2, which in our storing format means
// decreasing the score by 8.
// TODO: figure out what's wrong with this.
// return unigramFreq > 8 ? unigramFreq - 8 : (0 == unigramFreq ? 0 : 8);
}
// This returns a probability in log space.
inline int BinaryFormat::getProbability(const int position, const std::map<int, int> *bigramMap,
const uint8_t *bigramFilter, const int unigramFreq) {
if (!bigramMap || !bigramFilter) return unigramFreq;
if (!isInFilter(bigramFilter, position)) return unigramFreq;
const std::map<int, int>::const_iterator bigramFreq = bigramMap->find(position);
if (bigramFreq != bigramMap->end()) {
// TODO: return the frequency in bigramFreq->second
return unigramFreq;
if (!bigramMap || !bigramFilter) return backoff(unigramFreq);
if (!isInFilter(bigramFilter, position)) return backoff(unigramFreq);
const std::map<int, int>::const_iterator bigramFreqIt = bigramMap->find(position);
if (bigramFreqIt != bigramMap->end()) {
const int bigramFreq = bigramFreqIt->second;
// We divide the range [unigramFreq..255] in 16.5 steps - in other words, we want the
// unigram frequency to be the median value of the 17th step from the top. A value of
// 0 for the bigram frequency represents the middle of the 16th step from the top,
// while a value of 15 represents the middle of the top step.
// See makedict.BinaryDictInputOutput for details.
const float stepSize = ((float)MAX_FREQ - unigramFreq) / (1.5f + MAX_BIGRAM_FREQ);
return (int)(unigramFreq + bigramFreq * stepSize);
} else {
return unigramFreq;
return backoff(unigramFreq);
}
// TODO: if the unigram frequency is used, compute the actual probability
}
} // namespace latinime

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@ -207,6 +207,7 @@ static inline void prof_out(void) {
#define NEUTRAL_SCORE_SQUARED_RADIUS 8.0f
#define HALF_SCORE_SQUARED_RADIUS 32.0f
#define MAX_FREQ 255
#define MAX_BIGRAM_FREQ 15
// This must be greater than or equal to MAX_WORD_LENGTH defined in BinaryDictionary.java
// This is only used for the size of array. Not to be used in c functions.
@ -225,8 +226,8 @@ static inline void prof_out(void) {
#define MULTIPLE_WORDS_DEMOTION_RATE 80
#define MIN_INPUT_LENGTH_FOR_THREE_OR_MORE_WORDS_CORRECTION 6
#define TWO_WORDS_CORRECTION_WITH_OTHER_ERROR_THRESHOLD 0.39
#define START_TWO_WORDS_CORRECTION_THRESHOLD 0.22
#define TWO_WORDS_CORRECTION_WITH_OTHER_ERROR_THRESHOLD 0.35
#define START_TWO_WORDS_CORRECTION_THRESHOLD 0.185
#define MAX_DEPTH_MULTIPLIER 3