dlv.est {ccgarch} | R Documentation |
This function returns the gradient of the volatility part of the log-likelihood function of the DCC.
dlv.est(par, dvar, model)
par |
a vector of the volatility parameters |
dvar |
a matrix of the observed residuals (T times N) |
model |
a character string describing the model. "diagonal" for the diagonal model and "extended" for the extended (full ARCH and GARCH parameter matrices) model |
A vector of the gradient. (3N times 1) for "diagonal" and (2N^{2}+N times 1) for "diagonal".
The function can be called from optim
in dcc.estimation1
. For obtaining
the gradient for all t, use dlv
instead.
Engle, R.F. and K. Sheppard (2001), “Theoretical and Empirical Properties of Dynamic Conditional Correlation Multivariate GARCH.” Stern Finance Working Paper Series {FIN}-01-027 (Revised in Dec. 2001), New York University Stern School of Business.
Engle, R.F. (2002), “Dynamic Conditional Correlation: A Simple Class of Multivariate Generalized Autoregressive Conditional Heteroskedasticity Models.” Journal of Business and Economic Statistics 20, 339-350.
Hafner, C.M. and H. Herwartz (2008), “Analytical Quasi Maximum Likelihood Inference in Multivariate Volatility Models” Metrika 67, 219–239.