random_covmat
generates random VAR model \((dxd)\) error term covariance matrix \(\Omega\)
from (scaled) Wishart distribution, that is fairly close to the given matrix.
smart_covmat(d, Omega, accuracy)
number of time series in the system.
a symmetric positive definite \((dxd)\) covariance matrix specifying expected value of the matrix to be generated.
a positive real number adjusting how close to the given covariance matrix the returned individual should be. Standard deviation of each diagonal element is
\(\omega_{i,i}/\)accuracy
when accuracy > d/2
and sqrt(2/d)*
\(\omega_{i,i}\) when accuracy <= d/2
.
Wishart distribution is used, but for more details read the source code.
Returns \((d(d+1)/2x1)\) vector containing vech-vectorized covariance matrix \(\Omega\).