messageA character string giving any additional information
returned by the optimizer, or NULL. For details, see
PORT documentation.
iterationsNumber of iterations performed.
evaluationsNumber of objective function and gradient function
evaluations.
References
Nelson D.B. (1991);
Conditional Heteroscedasticity in Asset Returns: A New Approach,
Econometrica, 59, 347--370.
Fernandez C., Steel M.F.J. (2000);
On Bayesian Modelling of Fat Tails and Skewness,
Preprint, 31 pages.