Node:Iteration of the Minimization Algorithm, Next:Search Stopping Parameters for Minimization Algorithms, Previous:Providing the Function to be Minimized, Up:Nonlinear LeastSquares Fitting
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.
int gsl_multifit_fsolver_iterate (gsl_multifit_fsolver * s)  Function 
int gsl_multifit_fdfsolver_iterate (gsl_multifit_fdfsolver * s)  Function 
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 bestfit 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
gsl_multifit_fdfsolver
struct only)
The bestfit information also can be accessed with the following auxiliary functions,
gsl_vector * gsl_multifit_fsolver_position (const gsl_multifit_fsolver * s)  Function 
gsl_vector * gsl_multifit_fdfsolver_position (const gsl_multifit_fdfsolver * s)  Function 
These functions return the current position (i.e. bestfit parameters)
s>x of the solver s.
