灰色系统插值。alpha是包含α、μ值的矩阵；ago是预测后累加值矩阵；va是预测值矩阵；error是残差矩阵；c是后验差比值-Gray System interpolation. alpha is included in α, μ value matrix　ago was tired after the prediction value matrix　va is the prediction value matrix　error is the residual matrix　c is the ratio of posterior margin