PsiAR2 (mean, volatility, coef1, coef2, val0, val1)
where a1 + a2 < 1, a2 – a1 < 1 and -1 < a2 < 1 must be true for stationarity.
PsiAR2 produces a second order autoregressive time series with mean mean, volatility volatility, autoregressive coefficients coef1 and coef2 and time values val0 and val1.
An AR(2) time series is depicted by an autocorrelation function (ACF) that decreases geometrically and a partial autocorrelation function (PACF) that reduces to 0 after lag 2.
For more information, see the Analytic Solver Reference Guide downloadable from Analytic Solver by clicking Help -- User Guides -- Analytic Solver Reference Guide.