Check if a MixAR model is stable
isStable.Rd
Checks if a MixAR model is stable. This is also the second order stationarity condition.
Details
If each component of a MixAR model corresponds to a stable autoregression model, then the MixAR model is also stable. However, the MixAR model may be stable also when some of its components correspond to integrated or explosive AR models, see the references.
References
Boshnakov GN (2011). “On First and Second Order Stationarity of Random Coefficient Models.” Linear Algebra Appl., 434(2), 415--423. doi:10.1016/j.laa.2010.09.023 .
Wong CS, Li WK (2000). “On a mixture autoregressive model.” J. R. Stat. Soc., Ser. B, Stat. Methodol. , 62(1), 95-115.