Exercises
Here is a series of exercises. The answers to all the exercises are given in the Answers_to_Exercises_Chap6.ipynb
Jupyter notebook in the GitHub repository.
- For the AR(1) process defined by the following equation,
Eq. 35
show that and as , for any starting value . For this exercise you can assume that .
2. For the AR(1) process defined by the following equation,
Eq. 36
show that and as , for any starting value . For this exercise, you can assume that . See if you can derive the values of and for any value of , not just the asymptotically limiting values.
3. Use the ARIMA model form in Eq. 28 to generate a sample time series of length timepoints, that is of order , with coefficients . The noise values should be i.i.d. . You can set the first value, , of the generated series to zero. Use the statsmodels.tsa.arima.model.ARIMA
function from the statsmodels
package to fit an ARIMA(1,1,1) model to the simulated data you have just generated...