larch.ModelGroup.calculate_parameter_covariance#
- ModelGroup.calculate_parameter_covariance(pvals=None, *, robust=False)[source]#
Calculate the parameter covariance matrix.
- Parameters:
pvals (array-like, optional) – The parameter values to use in the calculation. If not given, the current parameter values are used.
robust (bool, default False) – Whether to calculate the robust covariance matrix.
- Returns:
se (array) – The standard errors of the parameter estimates.
hess (array) – The Hessian matrix.
ihess (array) – The inverse of the Hessian matrix.