int gauss_fdf (const gsl_vector * x, void *params,
gsl_vector * f, gsl_matrix * J)
{
gauss_f (x, params, f);
gauss_df (x, params, J);
return GSL_SUCCESS;
}
int gauss_fdf(const gsl_vector *parms, void *data, gsl_vector *f, gsl_matrix *J){
gauss_f(parms, data, f);
gauss_df(parms, data, J);
return GSL_SUCCESS;
}