ARIMA Models in R
David Stoffer
Professor of Statistics at the University of Pittsburgh

Consider pure seasonal models such as an SAR$(P = 1)_{s = 12}$
$$X_t = \Phi X_{t-12} + W_t$$

| $$SAR(P)_s$$ | $$SMA(Q)_s$$ | $$SARMA(P, Q)_s$$ | |
|---|---|---|---|
| ACF* | Tails off | Cuts off lag QS | Tails off |
| PACF* | Cuts off lag PS | Tails off | Tails off |

ARIMA Models in R