xref: /petsc/src/tao/complementarity/impls/ssls/ssfls.c (revision 76be6f4ff3bd4e251c19fc00ebbebfd58b6e7589)
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 
7   PetscFunctionBegin;
8   PetscCall(VecDuplicate(tao->solution,&tao->gradient));
9   PetscCall(VecDuplicate(tao->solution,&tao->stepdirection));
10   PetscCall(VecDuplicate(tao->solution,&ssls->w));
11   PetscCall(VecDuplicate(tao->solution,&ssls->ff));
12   PetscCall(VecDuplicate(tao->solution,&ssls->dpsi));
13   PetscCall(VecDuplicate(tao->solution,&ssls->da));
14   PetscCall(VecDuplicate(tao->solution,&ssls->db));
15   PetscCall(VecDuplicate(tao->solution,&ssls->t1));
16   PetscCall(VecDuplicate(tao->solution,&ssls->t2));
17   PetscCall(TaoLineSearchSetVariableBounds(tao->linesearch,tao->XL,tao->XU));
18   PetscFunctionReturn(0);
19 }
20 
21 static PetscErrorCode TaoSolve_SSFLS(Tao tao)
22 {
23   TAO_SSLS                     *ssls = (TAO_SSLS *)tao->data;
24   PetscReal                    psi, ndpsi, normd, innerd, t=0;
25   PetscReal                    delta, rho;
26   TaoLineSearchConvergedReason ls_reason;
27 
28   PetscFunctionBegin;
29   /* Assume that Setup has been called!
30      Set the structure for the Jacobian and create a linear solver. */
31   delta = ssls->delta;
32   rho = ssls->rho;
33 
34   PetscCall(TaoComputeVariableBounds(tao));
35   /* Project solution inside bounds */
36   PetscCall(VecMedian(tao->XL,tao->solution,tao->XU,tao->solution));
37   PetscCall(TaoLineSearchSetObjectiveAndGradientRoutine(tao->linesearch,Tao_SSLS_FunctionGradient,tao));
38   PetscCall(TaoLineSearchSetObjectiveRoutine(tao->linesearch,Tao_SSLS_Function,tao));
39 
40   /* Calculate the function value and fischer function value at the
41      current iterate */
42   PetscCall(TaoLineSearchComputeObjectiveAndGradient(tao->linesearch,tao->solution,&psi,ssls->dpsi));
43   PetscCall(VecNorm(ssls->dpsi,NORM_2,&ndpsi));
44 
45   tao->reason = TAO_CONTINUE_ITERATING;
46   while (PETSC_TRUE) {
47     PetscCall(PetscInfo(tao, "iter: %" PetscInt_FMT ", merit: %g, ndpsi: %g\n",tao->niter, (double)ssls->merit, (double)ndpsi));
48     /* Check the termination criteria */
49     PetscCall(TaoLogConvergenceHistory(tao,ssls->merit,ndpsi,0.0,tao->ksp_its));
50     PetscCall(TaoMonitor(tao,tao->niter,ssls->merit,ndpsi,0.0,t));
51     PetscCall((*tao->ops->convergencetest)(tao,tao->cnvP));
52     if (tao->reason!=TAO_CONTINUE_ITERATING) break;
53 
54     /* Call general purpose update function */
55     if (tao->ops->update) {
56       PetscCall((*tao->ops->update)(tao, tao->niter, tao->user_update));
57     }
58     tao->niter++;
59 
60     /* Calculate direction.  (Really negative of newton direction.  Therefore,
61        rest of the code uses -d.) */
62     PetscCall(KSPSetOperators(tao->ksp,tao->jacobian,tao->jacobian_pre));
63     PetscCall(KSPSolve(tao->ksp,ssls->ff,tao->stepdirection));
64     PetscCall(KSPGetIterationNumber(tao->ksp,&tao->ksp_its));
65     tao->ksp_tot_its+=tao->ksp_its;
66 
67     PetscCall(VecCopy(tao->stepdirection,ssls->w));
68     PetscCall(VecScale(ssls->w,-1.0));
69     PetscCall(VecBoundGradientProjection(ssls->w,tao->solution,tao->XL,tao->XU,ssls->w));
70 
71     PetscCall(VecNorm(ssls->w,NORM_2,&normd));
72     PetscCall(VecDot(ssls->w,ssls->dpsi,&innerd));
73 
74     /* Make sure that we have a descent direction */
75     if (innerd >= -delta*PetscPowReal(normd, rho)) {
76       PetscCall(PetscInfo(tao, "newton direction not descent\n"));
77       PetscCall(VecCopy(ssls->dpsi,tao->stepdirection));
78       PetscCall(VecDot(ssls->w,ssls->dpsi,&innerd));
79     }
80 
81     PetscCall(VecScale(tao->stepdirection, -1.0));
82     innerd = -innerd;
83 
84     PetscCall(TaoLineSearchSetInitialStepLength(tao->linesearch,1.0));
85     PetscCall(TaoLineSearchApply(tao->linesearch,tao->solution,&psi,ssls->dpsi,tao->stepdirection,&t,&ls_reason));
86     PetscCall(VecNorm(ssls->dpsi,NORM_2,&ndpsi));
87   }
88   PetscFunctionReturn(0);
89 }
90 
91 PetscErrorCode TaoDestroy_SSFLS(Tao tao)
92 {
93   TAO_SSLS       *ssls = (TAO_SSLS *)tao->data;
94 
95   PetscFunctionBegin;
96   PetscCall(VecDestroy(&ssls->ff));
97   PetscCall(VecDestroy(&ssls->w));
98   PetscCall(VecDestroy(&ssls->dpsi));
99   PetscCall(VecDestroy(&ssls->da));
100   PetscCall(VecDestroy(&ssls->db));
101   PetscCall(VecDestroy(&ssls->t1));
102   PetscCall(VecDestroy(&ssls->t2));
103   PetscCall(PetscFree(tao->data));
104   PetscFunctionReturn(0);
105 }
106 
107 /* ---------------------------------------------------------- */
108 /*MC
109    TAOSSFLS - Semi-smooth feasible linesearch algorithm for solving
110        complementarity constraints
111 
112    Options Database Keys:
113 + -tao_ssls_delta - descent test fraction
114 - -tao_ssls_rho - descent test power
115 
116    Level: beginner
117 M*/
118 
119 PETSC_EXTERN PetscErrorCode TaoCreate_SSFLS(Tao tao)
120 {
121   TAO_SSLS       *ssls;
122   const char     *armijo_type = TAOLINESEARCHARMIJO;
123 
124   PetscFunctionBegin;
125   PetscCall(PetscNewLog(tao,&ssls));
126   tao->data = (void*)ssls;
127   tao->ops->solve=TaoSolve_SSFLS;
128   tao->ops->setup=TaoSetUp_SSFLS;
129   tao->ops->view=TaoView_SSLS;
130   tao->ops->setfromoptions = TaoSetFromOptions_SSLS;
131   tao->ops->destroy = TaoDestroy_SSFLS;
132 
133   ssls->delta = 1e-10;
134   ssls->rho = 2.1;
135 
136   PetscCall(TaoLineSearchCreate(((PetscObject)tao)->comm,&tao->linesearch));
137   PetscCall(PetscObjectIncrementTabLevel((PetscObject)tao->linesearch, (PetscObject)tao, 1));
138   PetscCall(TaoLineSearchSetType(tao->linesearch,armijo_type));
139   PetscCall(TaoLineSearchSetOptionsPrefix(tao->linesearch,tao->hdr.prefix));
140   PetscCall(TaoLineSearchSetFromOptions(tao->linesearch));
141   /* Linesearch objective and objectivegradient routines are  set in solve routine */
142   PetscCall(KSPCreate(((PetscObject)tao)->comm,&tao->ksp));
143   PetscCall(PetscObjectIncrementTabLevel((PetscObject)tao->ksp, (PetscObject)tao, 1));
144   PetscCall(KSPSetOptionsPrefix(tao->ksp,tao->hdr.prefix));
145 
146   /* Override default settings (unless already changed) */
147   if (!tao->max_it_changed) tao->max_it = 2000;
148   if (!tao->max_funcs_changed) tao->max_funcs = 4000;
149   if (!tao->gttol_changed) tao->gttol = 0;
150   if (!tao->grtol_changed) tao->grtol = 0;
151 #if defined(PETSC_USE_REAL_SINGLE)
152   if (!tao->gatol_changed) tao->gatol = 1.0e-6;
153   if (!tao->fmin_changed)  tao->fmin = 1.0e-4;
154 #else
155   if (!tao->gatol_changed) tao->gatol = 1.0e-16;
156   if (!tao->fmin_changed)  tao->fmin = 1.0e-8;
157 #endif
158   PetscFunctionReturn(0);
159 }
160