Autoregressive–moving-average model

Summary

An autoregressive–moving-average model, or ARMA($p$, $q$) model, combines an autoregressive model of order $p$ with a moving-average model of order $q$. Each value is a linear combination of $p$ past values plus the current shock and $q$ past shocks. ARMA models describe a wide range of stationary time series with few parameters, and they are the core of the Box–Jenkins approach to forecasting.