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#include "CharDistribution.h"

#include "JISFreq.tab"

#include "Big5Freq.tab"

#include "EUCKRFreq.tab"

#include "EUCTWFreq.tab"

#include "GB2312Freq.tab"

#define SURE_YES 0.99f

#define SURE_NO  0.01f

#define MINIMUM_DATA_THRESHOLD  4

//return confidence base on received data

float CharDistributionAnalysis::GetConfidence(PRBool aIsPreferredLanguage)

{ 

  //if we didn't receive any character in our consideration range, or the

  // number of frequent characters is below the minimum threshold, return

  // negative answer

  if (mTotalChars <= 0 ||

      !aIsPreferredLanguage && mFreqChars <= MINIMUM_DATA_THRESHOLD)

    return SURE_NO;

  if (mTotalChars != mFreqChars) {

    float r = mFreqChars / ((mTotalChars - mFreqChars) * mTypicalDistributionRatio);

    if (r < SURE_YES)

      return r;

  }

  //normalize confidence, (we don't want to be 100% sure)

  return SURE_YES;

}

EUCTWDistributionAnalysis::EUCTWDistributionAnalysis()

{

  mCharToFreqOrder = EUCTWCharToFreqOrder;

  mTableSize = EUCTW_TABLE_SIZE;

  mTypicalDistributionRatio = EUCTW_TYPICAL_DISTRIBUTION_RATIO;

}

EUCKRDistributionAnalysis::EUCKRDistributionAnalysis()

{

  mCharToFreqOrder = EUCKRCharToFreqOrder;

  mTableSize = EUCKR_TABLE_SIZE;

  mTypicalDistributionRatio = EUCKR_TYPICAL_DISTRIBUTION_RATIO;

}

GB2312DistributionAnalysis::GB2312DistributionAnalysis()

{

  mCharToFreqOrder = GB2312CharToFreqOrder;

  mTableSize = GB2312_TABLE_SIZE;

  mTypicalDistributionRatio = GB2312_TYPICAL_DISTRIBUTION_RATIO;

}

Big5DistributionAnalysis::Big5DistributionAnalysis()

{

  mCharToFreqOrder = Big5CharToFreqOrder;

  mTableSize = BIG5_TABLE_SIZE;

  mTypicalDistributionRatio = BIG5_TYPICAL_DISTRIBUTION_RATIO;

}

SJISDistributionAnalysis::SJISDistributionAnalysis()

{

  mCharToFreqOrder = JISCharToFreqOrder;

  mTableSize = JIS_TABLE_SIZE;

  mTypicalDistributionRatio = JIS_TYPICAL_DISTRIBUTION_RATIO;

}

EUCJPDistributionAnalysis::EUCJPDistributionAnalysis()

{

  mCharToFreqOrder = JISCharToFreqOrder;

  mTableSize = JIS_TABLE_SIZE;

  mTypicalDistributionRatio = JIS_TYPICAL_DISTRIBUTION_RATIO;

}