说明：  离散灰色模型的计算程序，针对小样本时间序列的预测建模。本程序输出时间响应式拟合值、拟合效果图、和各种拟合精度指标值。
(Discrete gray model calculation program for small sample time series prediction modeling. The program output response time value style fitting, fitting renderings, and all kinds of fitting precision index value.)