xref: /petsc/src/tao/complementarity/impls/ssls/ssfls.c (revision 503c0ea9b45bcfbcebbb1ea5341243bbc69f0bea)
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   if (!tao->XL) {
18     PetscCall(VecDuplicate(tao->solution,&tao->XL));
19   }
20   if (!tao->XU) {
21     PetscCall(VecDuplicate(tao->solution,&tao->XU));
22   }
23   PetscCall(TaoLineSearchSetVariableBounds(tao->linesearch,tao->XL,tao->XU));
24   PetscFunctionReturn(0);
25 }
26 
27 static PetscErrorCode TaoSolve_SSFLS(Tao tao)
28 {
29   TAO_SSLS                     *ssls = (TAO_SSLS *)tao->data;
30   PetscReal                    psi, ndpsi, normd, innerd, t=0;
31   PetscReal                    delta, rho;
32   TaoLineSearchConvergedReason ls_reason;
33 
34   PetscFunctionBegin;
35   /* Assume that Setup has been called!
36      Set the structure for the Jacobian and create a linear solver. */
37   delta = ssls->delta;
38   rho = ssls->rho;
39 
40   PetscCall(TaoComputeVariableBounds(tao));
41   /* Project solution inside bounds */
42   PetscCall(VecMedian(tao->XL,tao->solution,tao->XU,tao->solution));
43   PetscCall(TaoLineSearchSetObjectiveAndGradientRoutine(tao->linesearch,Tao_SSLS_FunctionGradient,tao));
44   PetscCall(TaoLineSearchSetObjectiveRoutine(tao->linesearch,Tao_SSLS_Function,tao));
45 
46   /* Calculate the function value and fischer function value at the
47      current iterate */
48   PetscCall(TaoLineSearchComputeObjectiveAndGradient(tao->linesearch,tao->solution,&psi,ssls->dpsi));
49   PetscCall(VecNorm(ssls->dpsi,NORM_2,&ndpsi));
50 
51   tao->reason = TAO_CONTINUE_ITERATING;
52   while (PETSC_TRUE) {
53     PetscCall(PetscInfo(tao, "iter: %D, merit: %g, ndpsi: %g\n",tao->niter, (double)ssls->merit, (double)ndpsi));
54     /* Check the termination criteria */
55     PetscCall(TaoLogConvergenceHistory(tao,ssls->merit,ndpsi,0.0,tao->ksp_its));
56     PetscCall(TaoMonitor(tao,tao->niter,ssls->merit,ndpsi,0.0,t));
57     PetscCall((*tao->ops->convergencetest)(tao,tao->cnvP));
58     if (tao->reason!=TAO_CONTINUE_ITERATING) break;
59 
60     /* Call general purpose update function */
61     if (tao->ops->update) {
62       PetscCall((*tao->ops->update)(tao, tao->niter, tao->user_update));
63     }
64     tao->niter++;
65 
66     /* Calculate direction.  (Really negative of newton direction.  Therefore,
67        rest of the code uses -d.) */
68     PetscCall(KSPSetOperators(tao->ksp,tao->jacobian,tao->jacobian_pre));
69     PetscCall(KSPSolve(tao->ksp,ssls->ff,tao->stepdirection));
70     PetscCall(KSPGetIterationNumber(tao->ksp,&tao->ksp_its));
71     tao->ksp_tot_its+=tao->ksp_its;
72 
73     PetscCall(VecCopy(tao->stepdirection,ssls->w));
74     PetscCall(VecScale(ssls->w,-1.0));
75     PetscCall(VecBoundGradientProjection(ssls->w,tao->solution,tao->XL,tao->XU,ssls->w));
76 
77     PetscCall(VecNorm(ssls->w,NORM_2,&normd));
78     PetscCall(VecDot(ssls->w,ssls->dpsi,&innerd));
79 
80     /* Make sure that we have a descent direction */
81     if (innerd >= -delta*PetscPowReal(normd, rho)) {
82       PetscCall(PetscInfo(tao, "newton direction not descent\n"));
83       PetscCall(VecCopy(ssls->dpsi,tao->stepdirection));
84       PetscCall(VecDot(ssls->w,ssls->dpsi,&innerd));
85     }
86 
87     PetscCall(VecScale(tao->stepdirection, -1.0));
88     innerd = -innerd;
89 
90     PetscCall(TaoLineSearchSetInitialStepLength(tao->linesearch,1.0));
91     PetscCall(TaoLineSearchApply(tao->linesearch,tao->solution,&psi,ssls->dpsi,tao->stepdirection,&t,&ls_reason));
92     PetscCall(VecNorm(ssls->dpsi,NORM_2,&ndpsi));
93   }
94   PetscFunctionReturn(0);
95 }
96 
97 PetscErrorCode TaoDestroy_SSFLS(Tao tao)
98 {
99   TAO_SSLS       *ssls = (TAO_SSLS *)tao->data;
100 
101   PetscFunctionBegin;
102   PetscCall(VecDestroy(&ssls->ff));
103   PetscCall(VecDestroy(&ssls->w));
104   PetscCall(VecDestroy(&ssls->dpsi));
105   PetscCall(VecDestroy(&ssls->da));
106   PetscCall(VecDestroy(&ssls->db));
107   PetscCall(VecDestroy(&ssls->t1));
108   PetscCall(VecDestroy(&ssls->t2));
109   PetscCall(PetscFree(tao->data));
110   PetscFunctionReturn(0);
111 }
112 
113 /* ---------------------------------------------------------- */
114 /*MC
115    TAOSSFLS - Semi-smooth feasible linesearch algorithm for solving
116        complementarity constraints
117 
118    Options Database Keys:
119 + -tao_ssls_delta - descent test fraction
120 - -tao_ssls_rho - descent test power
121 
122    Level: beginner
123 M*/
124 
125 PETSC_EXTERN PetscErrorCode TaoCreate_SSFLS(Tao tao)
126 {
127   TAO_SSLS       *ssls;
128   const char     *armijo_type = TAOLINESEARCHARMIJO;
129 
130   PetscFunctionBegin;
131   PetscCall(PetscNewLog(tao,&ssls));
132   tao->data = (void*)ssls;
133   tao->ops->solve=TaoSolve_SSFLS;
134   tao->ops->setup=TaoSetUp_SSFLS;
135   tao->ops->view=TaoView_SSLS;
136   tao->ops->setfromoptions = TaoSetFromOptions_SSLS;
137   tao->ops->destroy = TaoDestroy_SSFLS;
138 
139   ssls->delta = 1e-10;
140   ssls->rho = 2.1;
141 
142   PetscCall(TaoLineSearchCreate(((PetscObject)tao)->comm,&tao->linesearch));
143   PetscCall(PetscObjectIncrementTabLevel((PetscObject)tao->linesearch, (PetscObject)tao, 1));
144   PetscCall(TaoLineSearchSetType(tao->linesearch,armijo_type));
145   PetscCall(TaoLineSearchSetOptionsPrefix(tao->linesearch,tao->hdr.prefix));
146   PetscCall(TaoLineSearchSetFromOptions(tao->linesearch));
147   /* Linesearch objective and objectivegradient routines are  set in solve routine */
148   PetscCall(KSPCreate(((PetscObject)tao)->comm,&tao->ksp));
149   PetscCall(PetscObjectIncrementTabLevel((PetscObject)tao->ksp, (PetscObject)tao, 1));
150   PetscCall(KSPSetOptionsPrefix(tao->ksp,tao->hdr.prefix));
151 
152   /* Override default settings (unless already changed) */
153   if (!tao->max_it_changed) tao->max_it = 2000;
154   if (!tao->max_funcs_changed) tao->max_funcs = 4000;
155   if (!tao->gttol_changed) tao->gttol = 0;
156   if (!tao->grtol_changed) tao->grtol = 0;
157 #if defined(PETSC_USE_REAL_SINGLE)
158   if (!tao->gatol_changed) tao->gatol = 1.0e-6;
159   if (!tao->fmin_changed)  tao->fmin = 1.0e-4;
160 #else
161   if (!tao->gatol_changed) tao->gatol = 1.0e-16;
162   if (!tao->fmin_changed)  tao->fmin = 1.0e-8;
163 #endif
164   PetscFunctionReturn(0);
165 }
166