statsmodels.tsa.statespace.sarimax.SARIMAX.transform_jacobian

SARIMAX.transform_jacobian(unconstrained, approx_centered=False)

Jacobian matrix for the parameter transformation function

Parameters:	unconstrained (array_like) – Array of unconstrained parameters used by the optimizer.
Returns:	jacobian – Jacobian matrix of the transformation, evaluated at `unconstrained`
Return type:	array

Notes

This is a numerical approximation using finite differences. Note that in general complex step methods cannot be used because it is not guaranteed that the transform_params method is a real function (e.g. if Cholesky decomposition is used).