12.6 Exercises
Compare STL and Dynamic Harmonic Regression forecasts for one of the series in the
pedestrian
data set.- Try modifying the order of the Fourier terms to minimize the AICc value.
- Check the residuals for each model. Do they capture the available information in the data?
- Which of the two sets of forecasts are best? Explain.
Consider the weekly data on US finished motor gasoline products supplied (millions of barrels per day) (series
us_gasoline
):- Fit a dynamic harmonic regression model to these data. How does it compare to the regression model you fitted in Exercise 5 in Section 7.10?
- Check the residuals from both models and comment on what you see.
- Could you model these data using any of the other methods we have considered in this book? Explain why/why not.
Experiment with using
NNETAR()
on your retail data and other data we have considered in previous chapters.