Differences chosen by the KPSS test and by the strength of seasonality, orders by a stepwise search on the information criterion (Hyndman & Khandakar, 2008). In a backtest the choice is made again at every origin, so the whole procedure is judged, not one lucky specification.
Arguments
- criterion
"aicc","aic"or"bic".- d, seasonal_d
Fix the number of differences instead of testing.
- max_order
Largest p, q, P and Q.
- regressors
External variables, a data frame, matrix or named list of numeric columns with one row per period from the first observation on; to forecast, the rows must also cover the horizon. The model becomes a regression with ARIMA errors. See
fourier_terms().
Value
A model specification, to use with fit_model(),
forecast_model() or backtest().