when to use seasonal dummy why use seasonal dummies in r what is the structure of the time series in r how often to cross validate seasonal data in r r what is the cross validation of the period when do i use seasonal dummies in r? when to cross validate seasonal seasonal variable in r x vs y in r what is the r model for predicting seasonal seasonality why are seasonal variables useful during cross validation how to cross validation period in r what is a one period cross validation which r variable is used to predict a seasonal time series? when does seasonal dummy in r come in can i use seasonal dummies in r r cross validation of time series r - how long is a forecast when is seasonal dummy in r how to cross validation time series what type of data is in cross validation