arima seasonal covariates when do you decompose seasonal covariates? how to cite seasonal covariates in a r model? arima seasonal covariates definition how to decompose seasonal variables in arima how to assess seasonal variation how to assess seasonal covariate why is it necessary to decompose seasonal data before fitting the arima time series model? how to assess seasonal covariates in arima model how to assess seasonal covariate model what is arima seasonal what is the seasonal covariate in the arima model how do you assess seasonal covariates arima seasonal definition what is the seasonality of the covariate how to assess seasonal covariates how to decompose seasonality using r what seasonal covariates in r when to use seasonal covariates for arima how to evaluate seasonal covariates in r