VAR_pcovmat
calculate the dp-dimensional covariance matrix of p consecutive
observations of a VAR process with the algorithm proposed by McElroy (2017).
VAR_pcovmat(p, d, all_Am, Omega_m)
Returns the \((dp \times dp)\) covariance matrix.
a positive integer specifying the autoregressive order
the number of time series in the system, i.e., the dimension
[d, d, p]
array containing the AR coefficient matrices
the \((d\times d)\) positive definite error term covariance matrix
Most of the code in this function is adapted from the one provided in the supplementary material of McElroy (2017). Reproduced under GNU General Public License, Copyright (2015) Tucker McElroy.
McElroy T. 2017. Computation of vector ARMA autocovariances. Statistics and Probability Letters, 124, 92-96.