xref: /petsc/src/tao/bound/impls/bqnls/bqnls.c (revision 6b5911594195c27bb116de24bb31df463a3cffa7)
1 #include <../src/tao/bound/impls/bqnk/bqnk.h>
2 
3 static PetscErrorCode TaoBQNLSComputeHessian(Tao tao)
4 {
5   TAO_BNK        *bnk = (TAO_BNK *)tao->data;
6   TAO_BQNK       *bqnk = (TAO_BQNK*)bnk->ctx;
7   PetscErrorCode ierr;
8 
9   PetscFunctionBegin;
10   ierr = MatLMVMUpdate(bqnk->B, tao->solution, bnk->unprojected_gradient);CHKERRQ(ierr);
11   PetscFunctionReturn(0);
12 }
13 
14 static PetscErrorCode TaoBQNLSComputeStep(Tao tao, PetscBool shift, KSPConvergedReason *ksp_reason, PetscInt *step_type)
15 {
16   TAO_BNK        *bnk = (TAO_BNK *)tao->data;
17   TAO_BQNK       *bqnk = (TAO_BQNK*)bnk->ctx;
18   PetscErrorCode ierr;
19 
20   PetscFunctionBegin;
21   ierr = MatSolve(bqnk->B, tao->gradient, tao->stepdirection);CHKERRQ(ierr);
22   ierr = VecScale(tao->stepdirection, -1.0);CHKERRQ(ierr);
23   ierr = TaoBNKBoundStep(tao, bnk->as_type, tao->stepdirection);CHKERRQ(ierr);
24   *ksp_reason = KSP_CONVERGED_ATOL;
25   *step_type = BNK_BFGS;
26   PetscFunctionReturn(0);
27 }
28 
29 static PetscErrorCode TaoSetUp_BQNLS(Tao tao)
30 {
31   TAO_BNK        *bnk = (TAO_BNK *)tao->data;
32   TAO_BQNK       *bqnk = (TAO_BQNK*)bnk->ctx;
33   PetscErrorCode ierr;
34 
35   PetscFunctionBegin;
36   ierr = TaoSetUp_BQNK(tao);CHKERRQ(ierr);
37   if (!bqnk->no_scale) {
38     ierr = MatSetOptionsPrefix(bqnk->Bscale, "tao_bqnls_scale_");CHKERRQ(ierr);
39     ierr = MatSetFromOptions(bqnk->Bscale);CHKERRQ(ierr);
40     ierr = MatSetType(bqnk->Bscale, MATLMVMDIAGBRDN);CHKERRQ(ierr);
41   }
42   PetscFunctionReturn(0);
43 }
44 
45 static PetscErrorCode TaoSetFromOptions_BQNLS(PetscOptionItems *PetscOptionsObject,Tao tao)
46 {
47   TAO_BNK        *bnk = (TAO_BNK *)tao->data;
48   TAO_BQNK       *bqnk = (TAO_BQNK*)bnk->ctx;
49   PetscErrorCode ierr;
50   KSPType        ksp_type;
51   PetscBool      is_spd;
52 
53   PetscFunctionBegin;
54   ierr = PetscOptionsHead(PetscOptionsObject,"Quasi-Newton-Krylov method for bound constrained optimization");CHKERRQ(ierr);
55   ierr = PetscOptionsEList("-tao_bqnls_as_type", "active set estimation method", "", BNK_AS, BNK_AS_TYPES, BNK_AS[bnk->as_type], &bnk->as_type, 0);CHKERRQ(ierr);
56   ierr = PetscOptionsReal("-tao_bqnls_epsilon", "(developer) tolerance used when computing actual and predicted reduction", "", bnk->epsilon, &bnk->epsilon,NULL);CHKERRQ(ierr);
57   ierr = PetscOptionsReal("-tao_bqnls_as_tol", "(developer) initial tolerance used when estimating actively bounded variables", "", bnk->as_tol, &bnk->as_tol,NULL);CHKERRQ(ierr);
58   ierr = PetscOptionsReal("-tao_bqnls_as_step", "(developer) step length used when estimating actively bounded variables", "", bnk->as_step, &bnk->as_step,NULL);CHKERRQ(ierr);
59   ierr = PetscOptionsInt("-tao_bqnls_max_cg_its", "number of BNCG iterations to take for each Newton step", "", bnk->max_cg_its, &bnk->max_cg_its,NULL);CHKERRQ(ierr);
60   ierr = PetscOptionsBool("-tao_bqnls_no_scale","(developer) disable the diagonal Broyden scaling of the BFGS approximation","",bqnk->no_scale,&bqnk->no_scale,NULL);CHKERRQ(ierr);
61   ierr = PetscOptionsTail();CHKERRQ(ierr);
62   ierr = TaoSetFromOptions(bnk->bncg);CHKERRQ(ierr);
63   ierr = TaoLineSearchSetFromOptions(tao->linesearch);CHKERRQ(ierr);
64   ierr = KSPSetFromOptions(tao->ksp);CHKERRQ(ierr);
65   ierr = KSPGetType(tao->ksp,&ksp_type);CHKERRQ(ierr);
66   bnk->is_nash = bnk->is_gltr = bnk->is_stcg = PETSC_FALSE;
67   ierr = MatSetFromOptions(bqnk->B);CHKERRQ(ierr);
68   ierr = MatGetOption(bqnk->B, MAT_SPD, &is_spd);CHKERRQ(ierr);
69   if (!is_spd) SETERRQ(PetscObjectComm((PetscObject)tao), PETSC_ERR_ARG_INCOMP, "LMVM matrix must be symmetric positive-definite");
70   PetscFunctionReturn(0);
71 }
72 
73 PETSC_EXTERN PetscErrorCode TaoCreate_BQNLS(Tao tao)
74 {
75   TAO_BNK        *bnk;
76   TAO_BQNK       *bqnk;
77   PetscErrorCode ierr;
78 
79   PetscFunctionBegin;
80   ierr = TaoCreate_BQNK(tao);CHKERRQ(ierr);
81   ierr = KSPSetOptionsPrefix(tao->ksp, "unused");CHKERRQ(ierr);
82   tao->ops->solve = TaoSolve_BNLS;
83   tao->ops->setup = TaoSetUp_BQNLS;
84   tao->ops->setfromoptions = TaoSetFromOptions_BQNLS;
85 
86   bnk = (TAO_BNK*)tao->data;
87   bnk->update_type = BNK_UPDATE_STEP;
88   bnk->computehessian = TaoBQNLSComputeHessian;
89   bnk->computestep = TaoBQNLSComputeStep;
90 
91   bqnk = (TAO_BQNK*)bnk->ctx;
92   ierr = MatSetOptionsPrefix(bqnk->B, "tao_bqnls_");CHKERRQ(ierr);
93   ierr = MatSetType(bqnk->B, MATLMVMBFGS);CHKERRQ(ierr);
94   PetscFunctionReturn(0);
95 }