This functions calculates numerical gradient of log-likelihood of cDCC-GARCH model.
cdcc_gradient(param, ht, residuals, stdresids, uncR, d = 1e-05)
cDCC-GARCH parameters(alpha,beta)
matrix of conditional variance vectors (T by N)
matrix of residual(de-mean) returns (T by N)
matrix of standrdized(De-GARCH) residual returns (T by N)
unconditional correlation matrix of stdresids (N by N)
(log-lik(x+d) - log-lik(x))/d
numerical gradient of log-likelihood of cDCC-GARCH model(vector)