Type Definition liblbfgs_sys::lbfgs_progress_t

pub type lbfgs_progress_t = Option<unsafe extern "C" fn(instance: *mut c_void, x: *const lbfgsfloatval_t, g: *const lbfgsfloatval_t, fx: lbfgsfloatval_t, xnorm: lbfgsfloatval_t, gnorm: lbfgsfloatval_t, step: lbfgsfloatval_t, n: c_int, k: c_int, ls: c_int) -> c_int>;

Callback interface to receive the progress of the optimization process.

The lbfgs() function call this function for each iteration. Implementing this function, a client program can store or display the current progress of the optimization process.

@param instance The user data sent for lbfgs() function by the client. @param x The current values of variables. @param g The current gradient values of variables. @param fx The current value of the objective function. @param xnorm The Euclidean norm of the variables. @param gnorm The Euclidean norm of the gradients. @param step The line-search step used for this iteration. @param n The number of variables. @param k The iteration count. @param ls The number of evaluations called for this iteration. @retval int Zero to continue the optimization process. Returning a non-zero value will cancel the optimization process.