[Help-gsl] gsl_multifit_nlinear_fdf with combined function and Jacobian?

[Olaf Wucknitz]

Hi,

I wonder if there is a reason that gsl_multifit_nlinear_fdf does not 
include a pointer to a function that computes both the function and its 
Jacobian at the same time, because this is often more efficient than doing 
it separately.

gsl_multiroot_function_fdf does have this option.

Or can we assume that, e.g., whenever the function for the Jacobian is 
called, the function itself is called with the same parameters before so 
that one can reuse intermediate steps internally?

Cheers,
Olaf