说明：  ARMA模型拟分为（一）（二）两部分发布，第一部分主要包括ARMA模型简介，模拟ARMA数据、拟合ARMA模型,单纯的AR模型或MA模型的定阶。第二部分主要包括ARMA模型的定阶策略、模型选择、残差分析。
(ARMA model fitting is divided into two parts: (1) and (2). The first part mainly includes the introduction of ARMA model, ARMA data simulation, ARMA model fitting, AR model or MA model order.The second part mainly includes the fixed-order strategy, model selection and residual analysis of ARMA model.)