Obtain List of Jacobian Matrix Entries for Covariance Matrix
Source:R/satterthwaite.R
      h_jac_list.RdObtain the Jacobian matrices given the covariance function and variance parameters.
Arguments
- covbeta_fun
- ( - function)
 function calculating the covariance matrix of coefficients given variance parameters (- theta), see- h_covbeta_fun()to obtain this from a- mmrm_tmbobject.
- theta_est
- ( - numeric)
 variance parameters point estimate.