/**
         * Determines the coefficients (alpha) for the ARTA-Process.
         * */
        public static double[] ArAutocorrelationsToAlphas(double[] arAutocorrelations)
        {
            int dim = arAutocorrelations.Length;

            double[] alphas = new double[dim];

            RealMatrix psi = AutoCorrelation.GetCorrelationMatrix(arAutocorrelations);
            RealMatrix r   = new Array2DRowRealMatrix(arAutocorrelations).transpose();
            RealMatrix a   = r.multiply(new CholeskyDecomposition(psi).getSolver().getInverse());

            alphas = a.getRow(0);
            return(alphas);
        }