The function is a wrapper around several methods for calculating the numerical Hessian matrix. The function is meant for internal use and is not exported.
hessian(type, log_lik, param_free, method, optimizer)
A character string giving the method to use when approximating the Hessian. One of: "numderiv" or "maxlik".
A log-likelihood expression prepared by
A list of freely estimated parameters
A method for the approximation of the Hessian. Only necessary for the maxlik package
A character string giving the optimizer used