xref: /petsc/src/tao/bound/impls/bncg/bncg.h (revision efa12513287cff49a2b9648ae83199dcbfaad71a)
1 /*
2     Context for bound-constrained nonlinear conjugate gradient method
3  */
4 
5 
6 #ifndef __TAO_BNCG_H
7 #define __TAO_BNCG_H
8 
9 #include <petsc/private/taoimpl.h>
10 
11 typedef struct {
12   Mat B;
13   Mat pc;
14   Vec G_old, X_old, W, work;
15   Vec g_work, y_work, d_work;
16   Vec sk, yk;
17   Vec unprojected_gradient, unprojected_gradient_old;
18   Vec inactive_grad, inactive_step;
19 
20   IS  active_lower, active_upper, active_fixed, active_idx, inactive_idx, inactive_old, new_inactives;
21 
22   PetscReal alpha;                   /* convex ratio in the scalar scaling */
23   PetscReal hz_theta;
24   PetscReal xi;                      /* Parameter for KD, DK, and HZ methods. */
25   PetscReal theta;                   /* The convex combination parameter in the SSML_Broyden method. */
26   PetscReal zeta;                    /* Another parameter, exclusive to Kou-Dai, modifying the y_k scalar contribution */
27   PetscReal hz_eta, dk_eta;
28   PetscReal bfgs_scale, dfp_scale;   /* Scaling of the bfgs/dfp tau parameter in the bfgs and broyden methods. Default 1. */
29   PetscReal tau_bfgs, tau_dfp;
30   PetscReal as_step, as_tol, yts, yty, sts;
31   PetscReal f, delta_min, delta_max;
32   PetscReal epsilon;                 /* Machine precision unless changed by user */
33   PetscReal eps_23;                  /*  Two-thirds power of machine precision */
34 
35   PetscInt cg_type;                  /*  Formula to use */
36   PetscInt min_restart_num;         /* Restarts every x*n iterations, where n is the dimension */
37   PetscInt ls_fails, resets, descent_error, skipped_updates, pure_gd_steps;
38   PetscInt iter_quad, min_quad;      /* Dynamic restart variables in Dai-Kou, SIAM J. Optim. Vol 23, pp. 296-320, Algorithm 4.1 */
39   PetscInt as_type;
40 
41   PetscBool inv_sig;
42   PetscReal tol_quad;                /* tolerance for Dai-Kou dynamic restart */
43   PetscBool dynamic_restart;         /* Keeps track of whether or not to do a dynamic (KD) restart */
44   PetscBool spaced_restart;          /* If true, restarts the CG method every x*n iterations */
45   PetscBool use_dynamic_restart;
46   PetscBool neg_xi;
47   PetscBool unscaled_restart;        /* Gradient descent restarts are done without rescaling*/
48   PetscBool diag_scaling;
49   PetscBool no_scaling;
50 
51 } TAO_BNCG;
52 
53 #endif /* ifndef __TAO_BNCG_H */
54 
55 PETSC_INTERN PetscErrorCode TaoBNCGEstimateActiveSet(Tao, PetscInt);
56 PETSC_INTERN PetscErrorCode TaoBNCGBoundStep(Tao, PetscInt, Vec);
57 PETSC_INTERN PetscErrorCode TaoBNCGComputeScalarScaling(PetscReal, PetscReal, PetscReal, PetscReal*, PetscReal);
58 PETSC_INTERN PetscErrorCode TaoBNCGConductIteration(Tao, PetscReal);
59 PETSC_INTERN PetscErrorCode TaoBNCGStepDirectionUpdate(Tao, PetscReal, PetscReal, PetscReal, PetscReal, PetscReal, PetscBool);
60 PETSC_INTERN PetscErrorCode TaoBNCGComputeDiagScaling(Tao, PetscReal, PetscReal);
61 PETSC_INTERN PetscErrorCode TaoBNCGResetUpdate(Tao, PetscReal);
62 PETSC_INTERN PetscErrorCode TaoBNCGCheckDynamicRestart(Tao, PetscReal, PetscReal, PetscReal, PetscBool*, PetscReal);
63