The following functions drive the iteration of each algorithm. Each function performs one iteration to update the state of any solver of the corresponding type. The same functions work for all solvers so that different methods can be substituted at runtime without modifications to the code.
These functions perform a single iteration of the solver s. If the iteration encounters an unexpected problem then an error code will be returned. The solver maintains a current estimate of the best-fit parameters at all times.
The solver struct s contains the following entries, which can be used to track the progress of the solution:
gsl_vector * x
gsl_vector * f
gsl_vector * dx
gsl_matrix * J
The best-fit information also can be accessed with the following auxiliary functions,
These functions return the current position (i.e. best-fit parameters)
s->xof the solver s.