Check for identifiability of fixed effects Originally provided by https://github.com/kaskr/TMB_contrib_R/TMBhelper Internal function called by fit_tmb.

check_estimability calculates the matrix of second-derivatives of the marginal likelihood w.r.t. fixed effects, to see if any linear combinations are not estimable (i.e. cannot be uniquely estimated conditional upon model structure and available data, e.g., resulting in a likelihood ridge and singular, non-invertable Hessian matrix)

check_estimability(obj, h)

Arguments

obj

The compiled object

h

optional argument containing pre-computed Hessian matrix

Value

A tagged list of the hessian and the message