peng04.logic.NGramCache.Increment C# (CSharp) Method

        public void Increment(IEnumerable<string> ngram, double amount)
        {
            Increment(ngram, amount, ngram);
        }

        private double GetBeta(string[] ngram)
        {
            string[] shortGram = ngram.GetNGram(0, ngram.Length - 1);

            double beta;

            if (_betaCache.TryFindValue(shortGram, out beta) && beta != 0)
            {
                return(beta);
            }

            double a = 0.0, b = 0.0;

            foreach (var item in _referenceSource.GetAllSegments())
            {
                ngram[ngram.Length - 1] = item; // replace last segment
                int frequencyA = _referenceSource.FindOccurrences(ngram);

                if (frequencyA > 0)
                {
                    var bNGram     = ngram.GetNGram(1, ngram.Length - 1);
                    int frequencyB = _referenceSource.FindOccurrences(bNGram);

                    a += GetProbabilityIfPresent(ngram, frequencyA);
                    b += GetProbabilityIfPresent(bNGram, frequencyB);
                }
            }

            beta = (1.0 - a) / (1.0 - b);
            _betaCache.Increment(shortGram, beta);
            return(beta);
        }