xref: /petsc/src/tao/complementarity/impls/ssls/ssfls.c (revision 609bdbee21ea3be08735c64dbe00a9ab27759925)
1 #include <../src/tao/complementarity/impls/ssls/ssls.h>
2 
3 PetscErrorCode TaoSetUp_SSFLS(Tao tao)
4 {
5   TAO_SSLS       *ssls = (TAO_SSLS *)tao->data;
6   PetscErrorCode ierr;
7 
8   PetscFunctionBegin;
9   ierr = VecDuplicate(tao->solution,&tao->gradient);CHKERRQ(ierr);
10   ierr = VecDuplicate(tao->solution,&tao->stepdirection);CHKERRQ(ierr);
11   ierr = VecDuplicate(tao->solution,&ssls->w);CHKERRQ(ierr);
12   ierr = VecDuplicate(tao->solution,&ssls->ff);CHKERRQ(ierr);
13   ierr = VecDuplicate(tao->solution,&ssls->dpsi);CHKERRQ(ierr);
14   ierr = VecDuplicate(tao->solution,&ssls->da);CHKERRQ(ierr);
15   ierr = VecDuplicate(tao->solution,&ssls->db);CHKERRQ(ierr);
16   ierr = VecDuplicate(tao->solution,&ssls->t1);CHKERRQ(ierr);
17   ierr = VecDuplicate(tao->solution,&ssls->t2);CHKERRQ(ierr);
18   if (!tao->XL) {
19     ierr = VecDuplicate(tao->solution,&tao->XL);CHKERRQ(ierr);
20   }
21   if (!tao->XU) {
22     ierr = VecDuplicate(tao->solution,&tao->XU);CHKERRQ(ierr);
23   }
24   ierr = TaoLineSearchSetVariableBounds(tao->linesearch,tao->XL,tao->XU);CHKERRQ(ierr);
25   PetscFunctionReturn(0);
26 }
27 
28 static PetscErrorCode TaoSolve_SSFLS(Tao tao)
29 {
30   TAO_SSLS                     *ssls = (TAO_SSLS *)tao->data;
31   PetscReal                    psi, ndpsi, normd, innerd, t=0;
32   PetscReal                    delta, rho;
33   TaoConvergedReason           reason;
34   TaoLineSearchConvergedReason ls_reason;
35   PetscErrorCode               ierr;
36 
37   PetscFunctionBegin;
38   /* Assume that Setup has been called!
39      Set the structure for the Jacobian and create a linear solver. */
40   delta = ssls->delta;
41   rho = ssls->rho;
42 
43   ierr = TaoComputeVariableBounds(tao);CHKERRQ(ierr);
44   /* Project solution inside bounds */
45   ierr = VecMedian(tao->XL,tao->solution,tao->XU,tao->solution);CHKERRQ(ierr);
46   ierr = TaoLineSearchSetObjectiveAndGradientRoutine(tao->linesearch,Tao_SSLS_FunctionGradient,tao);CHKERRQ(ierr);
47   ierr = TaoLineSearchSetObjectiveRoutine(tao->linesearch,Tao_SSLS_Function,tao);CHKERRQ(ierr);
48 
49   /* Calculate the function value and fischer function value at the
50      current iterate */
51   ierr = TaoLineSearchComputeObjectiveAndGradient(tao->linesearch,tao->solution,&psi,ssls->dpsi);CHKERRQ(ierr);
52   ierr = VecNorm(ssls->dpsi,NORM_2,&ndpsi);CHKERRQ(ierr);
53 
54   while (PETSC_TRUE) {
55     ierr=PetscInfo3(tao, "iter: %D, merit: %g, ndpsi: %g\n",tao->niter, (double)ssls->merit, (double)ndpsi);CHKERRQ(ierr);
56     /* Check the termination criteria */
57     ierr = TaoMonitor(tao,tao->niter,ssls->merit,ndpsi,0.0,t,&reason);CHKERRQ(ierr);
58     if (reason!=TAO_CONTINUE_ITERATING) break;
59     tao->niter++;
60 
61     /* Calculate direction.  (Really negative of newton direction.  Therefore,
62        rest of the code uses -d.) */
63     ierr = KSPSetOperators(tao->ksp,tao->jacobian,tao->jacobian_pre);CHKERRQ(ierr);
64     ierr = KSPSolve(tao->ksp,ssls->ff,tao->stepdirection);CHKERRQ(ierr);
65     ierr = KSPGetIterationNumber(tao->ksp,&tao->ksp_its);CHKERRQ(ierr);
66     tao->ksp_tot_its+=tao->ksp_its;
67 
68     ierr = VecCopy(tao->stepdirection,ssls->w);CHKERRQ(ierr);
69     ierr = VecScale(ssls->w,-1.0);CHKERRQ(ierr);
70     ierr = VecBoundGradientProjection(ssls->w,tao->solution,tao->XL,tao->XU,ssls->w);CHKERRQ(ierr);
71 
72     ierr = VecNorm(ssls->w,NORM_2,&normd);CHKERRQ(ierr);
73     ierr = VecDot(ssls->w,ssls->dpsi,&innerd);CHKERRQ(ierr);
74 
75     /* Make sure that we have a descent direction */
76     if (innerd >= -delta*PetscPowReal(normd, rho)) {
77       ierr = PetscInfo(tao, "newton direction not descent\n");CHKERRQ(ierr);
78       ierr = VecCopy(ssls->dpsi,tao->stepdirection);CHKERRQ(ierr);
79       ierr = VecDot(ssls->w,ssls->dpsi,&innerd);CHKERRQ(ierr);
80     }
81 
82     ierr = VecScale(tao->stepdirection, -1.0);CHKERRQ(ierr);
83     innerd = -innerd;
84 
85     ierr = TaoLineSearchSetInitialStepLength(tao->linesearch,1.0);CHKERRQ(ierr);
86     ierr = TaoLineSearchApply(tao->linesearch,tao->solution,&psi,ssls->dpsi,tao->stepdirection,&t,&ls_reason);CHKERRQ(ierr);
87     ierr = VecNorm(ssls->dpsi,NORM_2,&ndpsi);CHKERRQ(ierr);
88   }
89   PetscFunctionReturn(0);
90 }
91 
92 PetscErrorCode TaoDestroy_SSFLS(Tao tao)
93 {
94   TAO_SSLS       *ssls = (TAO_SSLS *)tao->data;
95   PetscErrorCode ierr;
96 
97   PetscFunctionBegin;
98   ierr = VecDestroy(&ssls->ff);CHKERRQ(ierr);
99   ierr = VecDestroy(&ssls->w);CHKERRQ(ierr);
100   ierr = VecDestroy(&ssls->dpsi);CHKERRQ(ierr);
101   ierr = VecDestroy(&ssls->da);CHKERRQ(ierr);
102   ierr = VecDestroy(&ssls->db);CHKERRQ(ierr);
103   ierr = VecDestroy(&ssls->t1);CHKERRQ(ierr);
104   ierr = VecDestroy(&ssls->t2);CHKERRQ(ierr);
105   ierr = PetscFree(tao->data);CHKERRQ(ierr);
106   PetscFunctionReturn(0);
107 }
108 
109 /* ---------------------------------------------------------- */
110 /*MC
111    TAOSSFLS - Semi-smooth feasible linesearch algorithm for solving
112        complementarity constraints
113 
114    Options Database Keys:
115 + -tao_ssls_delta - descent test fraction
116 - -tao_ssls_rho - descent test power
117 
118    Level: beginner
119 M*/
120 
121 PETSC_EXTERN PetscErrorCode TaoCreate_SSFLS(Tao tao)
122 {
123   TAO_SSLS       *ssls;
124   PetscErrorCode ierr;
125   const char     *armijo_type = TAOLINESEARCHARMIJO;
126 
127   PetscFunctionBegin;
128   ierr = PetscNewLog(tao,&ssls);CHKERRQ(ierr);
129   tao->data = (void*)ssls;
130   tao->ops->solve=TaoSolve_SSFLS;
131   tao->ops->setup=TaoSetUp_SSFLS;
132   tao->ops->view=TaoView_SSLS;
133   tao->ops->setfromoptions = TaoSetFromOptions_SSLS;
134   tao->ops->destroy = TaoDestroy_SSFLS;
135 
136   ssls->delta = 1e-10;
137   ssls->rho = 2.1;
138 
139   ierr = TaoLineSearchCreate(((PetscObject)tao)->comm,&tao->linesearch);CHKERRQ(ierr);
140   ierr = TaoLineSearchSetType(tao->linesearch,armijo_type);CHKERRQ(ierr);
141   ierr = TaoLineSearchSetOptionsPrefix(tao->linesearch,tao->hdr.prefix);CHKERRQ(ierr);
142   ierr = TaoLineSearchSetFromOptions(tao->linesearch);CHKERRQ(ierr);
143   /* Linesearch objective and objectivegradient routines are  set in solve routine */
144   ierr = KSPCreate(((PetscObject)tao)->comm,&tao->ksp);CHKERRQ(ierr);
145   ierr = KSPSetOptionsPrefix(tao->ksp,tao->hdr.prefix);CHKERRQ(ierr);
146 
147   /* Override default settings (unless already changed) */
148   if (!tao->max_it_changed) tao->max_it = 2000;
149   if (!tao->max_funcs_changed) tao->max_funcs = 4000;
150   if (!tao->gttol_changed) tao->gttol = 0;
151   if (!tao->grtol_changed) tao->grtol = 0;
152 #if defined(PETSC_USE_REAL_SINGLE)
153   if (!tao->gatol_changed) tao->gatol = 1.0e-6;
154   if (!tao->fmin_changed)  tao->fmin = 1.0e-4;
155 #else
156   if (!tao->gatol_changed) tao->gatol = 1.0e-16;
157   if (!tao->fmin_changed)  tao->fmin = 1.0e-8;
158 #endif
159   PetscFunctionReturn(0);
160 }
161 
162 
163