Fit a Generalized Additive Model (GAM) using
gam with a spline over time/years
gam_ts(timeseries, num_ahead = 5, level = 95)
| timeseries | the time series to forecast |
|---|---|
| num_ahead | the number of points at the end of the time series to forecast |
| level | Confidence level for prediction intervals. |
a data.frame of the mean forecasts, the observed values, and the lower and upper CI levels (if an error occurs, then just NA values)