df_b: the degrees of freedom for natural cubic splines. Default is 10.
grid: the number of gird points used to construct the functional time series and noise process. Default is 1000.
Returns
The function returns a list with components: - phi_coef: the estimated spline coefficients for convolutional function values, a (2*grid+1)-by-p matrix.
phi_func: the estimated convolutional function(s), a (df_b+1)-by-p matrix.
rho: estimated rho for O-U process (noise process).
sigma: estimated sigma for O-U process (noise process).
References
Liu, X., Xiao, H., and Chen, R. (2016) Convolutional autoregressive models for functional time series. Journal of Econometrics, 194, 263-282.