time series - Model specification for seasonal ARMA-GARCH ...
stats.stackexchange.com › questions › 501291Dec 17, 2020 · diff %>% auto.arima(trace = TRUE, approximation = T, stepwise = T, seasonal = F, #set to false since the goal is to account for seasonality by incorporating Fourier terms in the model. SARIMA(p, d, q)(P, D, Q)[24] parameters aren't supported by `rugarch`, thus ARMA terms plus adequate external regressors are needed.