Hi Seemant,
You can perform the GARCH-ARIMA modelling in MATLAB, using the Econometric Toolbox. The ‘arima’ function in MATLAB helps to estimate the parameters of the ARIMA model. The residuals from the ARIMA model can then be used to fit a GARCH(1,1) model with ‘garch’ function. This allows for forecasting future values and volatility of the series.
Note: Since MATLAB does not support an automatic function, you may need to try different combinations of ‘p’, ‘d’, ‘q’, using criterias like AIC (Akaike Information Criterion), BIC (Bayesian Information Criterion), Autocorrelation functions like ‘autocorr’ and ‘parcorr’, etc.
You may go through the following MathWorks documentation link to learn more about GARCH-ARIMA modelling in MATLAB.
- ‘arima’: https://www.mathworks.com/help/econ/arima.html
- Estimate ARIMA models: https://www.mathworks.com/help/ident/ug/estimating-arima-models.html
- ‘garch’: https://www.mathworks.com/help/econ/garch.html
- Specify GARCH models: https://www.mathworks.com/help/econ/specify-garch-models-using-garch.html
I hope this helps.