In the notebook MLest, we use
vcv_mle = results.hess_inv * OffDiagNeg
to obtain the VCV. However, results.hess_inv is not a ndarray but a scipy.optimize.LbfgsInvHessProduct object, which will interpret '' as dot multiplication instead of pointwise multiplication, thus generating irregular VCV result.
Instead, we should use:
`vcv_mle = results.hess_inv.todense() OffDiagNeg`
i.e., transform it to a dense matrix, and then do the pointwise multiplication.
In the notebook MLest, we use
vcv_mle = results.hess_inv * OffDiagNeg
to obtain the VCV. However,results.hess_inv
is not a ndarray but a scipy.optimize.LbfgsInvHessProduct object, which will interpret '' as dot multiplication instead of pointwise multiplication, thus generating irregular VCV result. Instead, we should use: `vcv_mle = results.hess_inv.todense() OffDiagNeg` i.e., transform it to a dense matrix, and then do the pointwise multiplication.