Actual source code: lcl.c

  1: #include <../src/tao/pde_constrained/impls/lcl/lcl.h>
  2: static PetscErrorCode LCLComputeLagrangianAndGradient(TaoLineSearch, Vec, PetscReal *, Vec, void *);
  3: static PetscErrorCode LCLComputeAugmentedLagrangianAndGradient(TaoLineSearch, Vec, PetscReal *, Vec, void *);
  4: static PetscErrorCode LCLScatter(TAO_LCL *, Vec, Vec, Vec);
  5: static PetscErrorCode LCLGather(TAO_LCL *, Vec, Vec, Vec);

  7: static PetscErrorCode TaoDestroy_LCL(Tao tao)
  8: {
  9:   TAO_LCL *lclP = (TAO_LCL *)tao->data;

 11:   PetscFunctionBegin;
 12:   if (tao->setupcalled) {
 13:     PetscCall(MatDestroy(&lclP->R));
 14:     PetscCall(VecDestroy(&lclP->lambda));
 15:     PetscCall(VecDestroy(&lclP->lambda0));
 16:     PetscCall(VecDestroy(&lclP->WL));
 17:     PetscCall(VecDestroy(&lclP->W));
 18:     PetscCall(VecDestroy(&lclP->X0));
 19:     PetscCall(VecDestroy(&lclP->G0));
 20:     PetscCall(VecDestroy(&lclP->GL));
 21:     PetscCall(VecDestroy(&lclP->GAugL));
 22:     PetscCall(VecDestroy(&lclP->dbar));
 23:     PetscCall(VecDestroy(&lclP->U));
 24:     PetscCall(VecDestroy(&lclP->U0));
 25:     PetscCall(VecDestroy(&lclP->V));
 26:     PetscCall(VecDestroy(&lclP->V0));
 27:     PetscCall(VecDestroy(&lclP->V1));
 28:     PetscCall(VecDestroy(&lclP->GU));
 29:     PetscCall(VecDestroy(&lclP->GV));
 30:     PetscCall(VecDestroy(&lclP->GU0));
 31:     PetscCall(VecDestroy(&lclP->GV0));
 32:     PetscCall(VecDestroy(&lclP->GL_U));
 33:     PetscCall(VecDestroy(&lclP->GL_V));
 34:     PetscCall(VecDestroy(&lclP->GAugL_U));
 35:     PetscCall(VecDestroy(&lclP->GAugL_V));
 36:     PetscCall(VecDestroy(&lclP->GL_U0));
 37:     PetscCall(VecDestroy(&lclP->GL_V0));
 38:     PetscCall(VecDestroy(&lclP->GAugL_U0));
 39:     PetscCall(VecDestroy(&lclP->GAugL_V0));
 40:     PetscCall(VecDestroy(&lclP->DU));
 41:     PetscCall(VecDestroy(&lclP->DV));
 42:     PetscCall(VecDestroy(&lclP->WU));
 43:     PetscCall(VecDestroy(&lclP->WV));
 44:     PetscCall(VecDestroy(&lclP->g1));
 45:     PetscCall(VecDestroy(&lclP->g2));
 46:     PetscCall(VecDestroy(&lclP->con1));

 48:     PetscCall(VecDestroy(&lclP->r));
 49:     PetscCall(VecDestroy(&lclP->s));

 51:     PetscCall(ISDestroy(&tao->state_is));
 52:     PetscCall(ISDestroy(&tao->design_is));

 54:     PetscCall(VecScatterDestroy(&lclP->state_scatter));
 55:     PetscCall(VecScatterDestroy(&lclP->design_scatter));
 56:   }
 57:   PetscCall(MatDestroy(&lclP->R));
 58:   PetscCall(KSPDestroy(&tao->ksp));
 59:   PetscCall(PetscFree(tao->data));
 60:   PetscFunctionReturn(PETSC_SUCCESS);
 61: }

 63: static PetscErrorCode TaoSetFromOptions_LCL(Tao tao, PetscOptionItems PetscOptionsObject)
 64: {
 65:   TAO_LCL *lclP = (TAO_LCL *)tao->data;

 67:   PetscFunctionBegin;
 68:   PetscOptionsHeadBegin(PetscOptionsObject, "Linearly-Constrained Augmented Lagrangian Method for PDE-constrained optimization");
 69:   PetscCall(PetscOptionsReal("-tao_lcl_eps1", "epsilon 1 tolerance", "", lclP->eps1, &lclP->eps1, NULL));
 70:   PetscCall(PetscOptionsReal("-tao_lcl_eps2", "epsilon 2 tolerance", "", lclP->eps2, &lclP->eps2, NULL));
 71:   PetscCall(PetscOptionsReal("-tao_lcl_rho0", "init value for rho", "", lclP->rho0, &lclP->rho0, NULL));
 72:   PetscCall(PetscOptionsReal("-tao_lcl_rhomax", "max value for rho", "", lclP->rhomax, &lclP->rhomax, NULL));
 73:   lclP->phase2_niter = 1;
 74:   PetscCall(PetscOptionsInt("-tao_lcl_phase2_niter", "Number of phase 2 iterations in LCL algorithm", "", lclP->phase2_niter, &lclP->phase2_niter, NULL));
 75:   lclP->verbose = PETSC_FALSE;
 76:   PetscCall(PetscOptionsBool("-tao_lcl_verbose", "Print verbose output", "", lclP->verbose, &lclP->verbose, NULL));
 77:   lclP->tau[0] = lclP->tau[1] = lclP->tau[2] = lclP->tau[3] = 1.0e-4;
 78:   PetscCall(PetscOptionsReal("-tao_lcl_tola", "Tolerance for first forward solve", "", lclP->tau[0], &lclP->tau[0], NULL));
 79:   PetscCall(PetscOptionsReal("-tao_lcl_tolb", "Tolerance for first adjoint solve", "", lclP->tau[1], &lclP->tau[1], NULL));
 80:   PetscCall(PetscOptionsReal("-tao_lcl_tolc", "Tolerance for second forward solve", "", lclP->tau[2], &lclP->tau[2], NULL));
 81:   PetscCall(PetscOptionsReal("-tao_lcl_told", "Tolerance for second adjoint solve", "", lclP->tau[3], &lclP->tau[3], NULL));
 82:   PetscOptionsHeadEnd();
 83:   PetscCall(TaoLineSearchSetFromOptions(tao->linesearch));
 84:   PetscCall(MatSetFromOptions(lclP->R));
 85:   PetscFunctionReturn(PETSC_SUCCESS);
 86: }

 88: static PetscErrorCode TaoView_LCL(Tao tao, PetscViewer viewer)
 89: {
 90:   return PETSC_SUCCESS;
 91: }

 93: static PetscErrorCode TaoSetup_LCL(Tao tao)
 94: {
 95:   TAO_LCL *lclP = (TAO_LCL *)tao->data;
 96:   PetscInt lo, hi, nlocalstate, nlocaldesign;
 97:   IS       is_state, is_design;

 99:   PetscFunctionBegin;
100:   PetscCheck(tao->state_is, PetscObjectComm((PetscObject)tao), PETSC_ERR_ARG_WRONGSTATE, "LCL Solver requires an initial state index set -- use TaoSetStateIS()");
101:   PetscCall(VecDuplicate(tao->solution, &tao->stepdirection));
102:   PetscCall(VecDuplicate(tao->solution, &lclP->W));
103:   PetscCall(VecDuplicate(tao->solution, &lclP->X0));
104:   PetscCall(VecDuplicate(tao->solution, &lclP->G0));
105:   PetscCall(VecDuplicate(tao->solution, &lclP->GL));
106:   PetscCall(VecDuplicate(tao->solution, &lclP->GAugL));

108:   PetscCall(VecDuplicate(tao->constraints, &lclP->lambda));
109:   PetscCall(VecDuplicate(tao->constraints, &lclP->WL));
110:   PetscCall(VecDuplicate(tao->constraints, &lclP->lambda0));
111:   PetscCall(VecDuplicate(tao->constraints, &lclP->con1));

113:   PetscCall(VecSet(lclP->lambda, 0.0));

115:   PetscCall(VecGetSize(tao->solution, &lclP->n));
116:   PetscCall(VecGetSize(tao->constraints, &lclP->m));

118:   PetscCall(VecCreate(((PetscObject)tao)->comm, &lclP->U));
119:   PetscCall(VecCreate(((PetscObject)tao)->comm, &lclP->V));
120:   PetscCall(ISGetLocalSize(tao->state_is, &nlocalstate));
121:   PetscCall(ISGetLocalSize(tao->design_is, &nlocaldesign));
122:   PetscCall(VecSetSizes(lclP->U, nlocalstate, lclP->m));
123:   PetscCall(VecSetSizes(lclP->V, nlocaldesign, lclP->n - lclP->m));
124:   PetscCall(VecSetType(lclP->U, ((PetscObject)tao->solution)->type_name));
125:   PetscCall(VecSetType(lclP->V, ((PetscObject)tao->solution)->type_name));
126:   PetscCall(VecSetFromOptions(lclP->U));
127:   PetscCall(VecSetFromOptions(lclP->V));
128:   PetscCall(VecDuplicate(lclP->U, &lclP->DU));
129:   PetscCall(VecDuplicate(lclP->U, &lclP->U0));
130:   PetscCall(VecDuplicate(lclP->U, &lclP->GU));
131:   PetscCall(VecDuplicate(lclP->U, &lclP->GU0));
132:   PetscCall(VecDuplicate(lclP->U, &lclP->GAugL_U));
133:   PetscCall(VecDuplicate(lclP->U, &lclP->GL_U));
134:   PetscCall(VecDuplicate(lclP->U, &lclP->GAugL_U0));
135:   PetscCall(VecDuplicate(lclP->U, &lclP->GL_U0));
136:   PetscCall(VecDuplicate(lclP->U, &lclP->WU));
137:   PetscCall(VecDuplicate(lclP->U, &lclP->r));
138:   PetscCall(VecDuplicate(lclP->V, &lclP->V0));
139:   PetscCall(VecDuplicate(lclP->V, &lclP->V1));
140:   PetscCall(VecDuplicate(lclP->V, &lclP->DV));
141:   PetscCall(VecDuplicate(lclP->V, &lclP->s));
142:   PetscCall(VecDuplicate(lclP->V, &lclP->GV));
143:   PetscCall(VecDuplicate(lclP->V, &lclP->GV0));
144:   PetscCall(VecDuplicate(lclP->V, &lclP->dbar));
145:   PetscCall(VecDuplicate(lclP->V, &lclP->GAugL_V));
146:   PetscCall(VecDuplicate(lclP->V, &lclP->GL_V));
147:   PetscCall(VecDuplicate(lclP->V, &lclP->GAugL_V0));
148:   PetscCall(VecDuplicate(lclP->V, &lclP->GL_V0));
149:   PetscCall(VecDuplicate(lclP->V, &lclP->WV));
150:   PetscCall(VecDuplicate(lclP->V, &lclP->g1));
151:   PetscCall(VecDuplicate(lclP->V, &lclP->g2));

153:   /* create scatters for state, design subvecs */
154:   PetscCall(VecGetOwnershipRange(lclP->U, &lo, &hi));
155:   PetscCall(ISCreateStride(((PetscObject)lclP->U)->comm, hi - lo, lo, 1, &is_state));
156:   PetscCall(VecGetOwnershipRange(lclP->V, &lo, &hi));
157:   if (0) {
158:     PetscInt sizeU, sizeV;
159:     PetscCall(VecGetSize(lclP->U, &sizeU));
160:     PetscCall(VecGetSize(lclP->V, &sizeV));
161:     PetscCall(PetscPrintf(PETSC_COMM_WORLD, "size(U)=%" PetscInt_FMT ", size(V)=%" PetscInt_FMT "\n", sizeU, sizeV));
162:   }
163:   PetscCall(ISCreateStride(((PetscObject)lclP->V)->comm, hi - lo, lo, 1, &is_design));
164:   PetscCall(VecScatterCreate(tao->solution, tao->state_is, lclP->U, is_state, &lclP->state_scatter));
165:   PetscCall(VecScatterCreate(tao->solution, tao->design_is, lclP->V, is_design, &lclP->design_scatter));
166:   PetscCall(ISDestroy(&is_state));
167:   PetscCall(ISDestroy(&is_design));
168:   PetscFunctionReturn(PETSC_SUCCESS);
169: }

171: static PetscErrorCode TaoSolve_LCL(Tao tao)
172: {
173:   TAO_LCL                     *lclP = (TAO_LCL *)tao->data;
174:   PetscInt                     phase2_iter, nlocal, its;
175:   TaoLineSearchConvergedReason ls_reason = TAOLINESEARCH_CONTINUE_ITERATING;
176:   PetscReal                    step      = 1.0, f, descent, aldescent;
177:   PetscReal                    cnorm, mnorm;
178:   PetscReal                    adec, r2, rGL_U, rWU;
179:   PetscBool                    set, pset, flag, pflag, symmetric;

181:   PetscFunctionBegin;
182:   lclP->rho = lclP->rho0;
183:   PetscCall(VecGetLocalSize(lclP->U, &nlocal));
184:   PetscCall(VecGetLocalSize(lclP->V, &nlocal));
185:   PetscCall(MatSetSizes(lclP->R, nlocal, nlocal, lclP->n - lclP->m, lclP->n - lclP->m));
186:   PetscCall(MatLMVMAllocate(lclP->R, lclP->V, lclP->V));
187:   lclP->recompute_jacobian_flag = PETSC_TRUE;

189:   /* Scatter to U,V */
190:   PetscCall(LCLScatter(lclP, tao->solution, lclP->U, lclP->V));

192:   /* Evaluate Function, Gradient, Constraints, and Jacobian */
193:   PetscCall(TaoComputeObjectiveAndGradient(tao, tao->solution, &f, tao->gradient));
194:   PetscCall(TaoComputeJacobianState(tao, tao->solution, tao->jacobian_state, tao->jacobian_state_pre, tao->jacobian_state_inv));
195:   PetscCall(TaoComputeJacobianDesign(tao, tao->solution, tao->jacobian_design));
196:   PetscCall(TaoComputeConstraints(tao, tao->solution, tao->constraints));

198:   /* Scatter gradient to GU,GV */
199:   PetscCall(LCLScatter(lclP, tao->gradient, lclP->GU, lclP->GV));

201:   /* Evaluate Lagrangian function and gradient */
202:   /* p0 */
203:   PetscCall(VecSet(lclP->lambda, 0.0)); /*  Initial guess in CG */
204:   PetscCall(MatIsSymmetricKnown(tao->jacobian_state, &set, &flag));
205:   if (tao->jacobian_state_pre) {
206:     PetscCall(MatIsSymmetricKnown(tao->jacobian_state_pre, &pset, &pflag));
207:   } else {
208:     pset = pflag = PETSC_TRUE;
209:   }
210:   if (set && pset && flag && pflag) symmetric = PETSC_TRUE;
211:   else symmetric = PETSC_FALSE;

213:   lclP->solve_type = LCL_ADJOINT2;
214:   if (tao->jacobian_state_inv) {
215:     if (symmetric) {
216:       PetscCall(MatMult(tao->jacobian_state_inv, lclP->GU, lclP->lambda));
217:     } else {
218:       PetscCall(MatMultTranspose(tao->jacobian_state_inv, lclP->GU, lclP->lambda));
219:     }
220:   } else {
221:     PetscCall(KSPSetOperators(tao->ksp, tao->jacobian_state, tao->jacobian_state_pre));
222:     if (symmetric) {
223:       PetscCall(KSPSolve(tao->ksp, lclP->GU, lclP->lambda));
224:     } else {
225:       PetscCall(KSPSolveTranspose(tao->ksp, lclP->GU, lclP->lambda));
226:     }
227:     PetscCall(KSPGetIterationNumber(tao->ksp, &its));
228:     tao->ksp_its += its;
229:     tao->ksp_tot_its += its;
230:   }
231:   PetscCall(VecCopy(lclP->lambda, lclP->lambda0));
232:   PetscCall(LCLComputeAugmentedLagrangianAndGradient(tao->linesearch, tao->solution, &lclP->aug, lclP->GAugL, tao));

234:   PetscCall(LCLScatter(lclP, lclP->GL, lclP->GL_U, lclP->GL_V));
235:   PetscCall(LCLScatter(lclP, lclP->GAugL, lclP->GAugL_U, lclP->GAugL_V));

237:   /* Evaluate constraint norm */
238:   PetscCall(VecNorm(tao->constraints, NORM_2, &cnorm));
239:   PetscCall(VecNorm(lclP->GAugL, NORM_2, &mnorm));

241:   /* Monitor convergence */
242:   tao->reason = TAO_CONTINUE_ITERATING;
243:   PetscCall(TaoLogConvergenceHistory(tao, f, mnorm, cnorm, tao->ksp_its));
244:   PetscCall(TaoMonitor(tao, tao->niter, f, mnorm, cnorm, step));
245:   PetscUseTypeMethod(tao, convergencetest, tao->cnvP);

247:   while (tao->reason == TAO_CONTINUE_ITERATING) {
248:     /* Call general purpose update function */
249:     PetscTryTypeMethod(tao, update, tao->niter, tao->user_update);
250:     tao->ksp_its = 0;
251:     /* Compute a descent direction for the linearly constrained subproblem
252:        minimize f(u+du, v+dv)
253:        s.t. A(u0,v0)du + B(u0,v0)dv = -g(u0,v0) */

255:     /* Store the points around the linearization */
256:     PetscCall(VecCopy(lclP->U, lclP->U0));
257:     PetscCall(VecCopy(lclP->V, lclP->V0));
258:     PetscCall(VecCopy(lclP->GU, lclP->GU0));
259:     PetscCall(VecCopy(lclP->GV, lclP->GV0));
260:     PetscCall(VecCopy(lclP->GAugL_U, lclP->GAugL_U0));
261:     PetscCall(VecCopy(lclP->GAugL_V, lclP->GAugL_V0));
262:     PetscCall(VecCopy(lclP->GL_U, lclP->GL_U0));
263:     PetscCall(VecCopy(lclP->GL_V, lclP->GL_V0));

265:     lclP->aug0 = lclP->aug;
266:     lclP->lgn0 = lclP->lgn;

268:     /* Given the design variables, we need to project the current iterate
269:        onto the linearized constraint.  We choose to fix the design variables
270:        and solve the linear system for the state variables.  The resulting
271:        point is the Newton direction */

273:     /* Solve r = A\con */
274:     lclP->solve_type = LCL_FORWARD1;
275:     PetscCall(VecSet(lclP->r, 0.0)); /*  Initial guess in CG */

277:     if (tao->jacobian_state_inv) {
278:       PetscCall(MatMult(tao->jacobian_state_inv, tao->constraints, lclP->r));
279:     } else {
280:       PetscCall(KSPSetOperators(tao->ksp, tao->jacobian_state, tao->jacobian_state_pre));
281:       PetscCall(KSPSolve(tao->ksp, tao->constraints, lclP->r));
282:       PetscCall(KSPGetIterationNumber(tao->ksp, &its));
283:       tao->ksp_its += its;
284:       tao->ksp_tot_its += tao->ksp_its;
285:     }

287:     /* Set design step direction dv to zero */
288:     PetscCall(VecSet(lclP->s, 0.0));

290:     /*
291:        Check sufficient descent for constraint merit function .5*||con||^2
292:        con' Ak r >= eps1 ||r||^(2+eps2)
293:     */

295:     /* Compute WU= Ak' * con */
296:     if (symmetric) {
297:       PetscCall(MatMult(tao->jacobian_state, tao->constraints, lclP->WU));
298:     } else {
299:       PetscCall(MatMultTranspose(tao->jacobian_state, tao->constraints, lclP->WU));
300:     }
301:     /* Compute r * Ak' * con */
302:     PetscCall(VecDot(lclP->r, lclP->WU, &rWU));

304:     /* compute ||r||^(2+eps2) */
305:     PetscCall(VecNorm(lclP->r, NORM_2, &r2));
306:     r2   = PetscPowScalar(r2, 2.0 + lclP->eps2);
307:     adec = lclP->eps1 * r2;

309:     if (rWU < adec) {
310:       PetscCall(PetscInfo(tao, "Newton direction not descent for constraint, feasibility phase required\n"));
311:       if (lclP->verbose) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Newton direction not descent for constraint: %g -- using steepest descent\n", (double)descent));

313:       PetscCall(PetscInfo(tao, "Using steepest descent direction instead.\n"));
314:       PetscCall(VecSet(lclP->r, 0.0));
315:       PetscCall(VecAXPY(lclP->r, -1.0, lclP->WU));
316:       PetscCall(VecDot(lclP->r, lclP->r, &rWU));
317:       PetscCall(VecNorm(lclP->r, NORM_2, &r2));
318:       r2 = PetscPowScalar(r2, 2.0 + lclP->eps2);
319:       PetscCall(VecDot(lclP->r, lclP->GAugL_U, &descent));
320:       adec = lclP->eps1 * r2;
321:     }

323:     /*
324:        Check descent for aug. lagrangian
325:        r' (GUk - Ak'*yk - rho*Ak'*con) <= -eps1 ||r||^(2+eps2)
326:           GL_U = GUk - Ak'*yk
327:           WU   = Ak'*con
328:                                          adec=eps1||r||^(2+eps2)

330:        ==>
331:        Check r'GL_U - rho*r'WU <= adec
332:     */

334:     PetscCall(VecDot(lclP->r, lclP->GL_U, &rGL_U));
335:     aldescent = rGL_U - lclP->rho * rWU;
336:     if (aldescent > -adec) {
337:       if (lclP->verbose) PetscCall(PetscPrintf(PETSC_COMM_WORLD, " Newton direction not descent for augmented Lagrangian: %g", (double)aldescent));
338:       PetscCall(PetscInfo(tao, "Newton direction not descent for augmented Lagrangian: %g\n", (double)aldescent));
339:       lclP->rho = (rGL_U - adec) / rWU;
340:       PetscCheck(lclP->rho <= lclP->rhomax, PETSC_COMM_WORLD, PETSC_ERR_SUP, "rho=%g > rhomax, case not implemented.  Increase rhomax (-tao_lcl_rhomax)", (double)lclP->rho);
341:       if (lclP->verbose) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "  Increasing penalty parameter to %g\n", (double)lclP->rho));
342:       PetscCall(PetscInfo(tao, "  Increasing penalty parameter to %g\n", (double)lclP->rho));
343:     }

345:     PetscCall(LCLComputeAugmentedLagrangianAndGradient(tao->linesearch, tao->solution, &lclP->aug, lclP->GAugL, tao));
346:     PetscCall(LCLScatter(lclP, lclP->GL, lclP->GL_U, lclP->GL_V));
347:     PetscCall(LCLScatter(lclP, lclP->GAugL, lclP->GAugL_U, lclP->GAugL_V));

349:     /* We now minimize the augmented Lagrangian along the Newton direction */
350:     PetscCall(VecScale(lclP->r, -1.0));
351:     PetscCall(LCLGather(lclP, lclP->r, lclP->s, tao->stepdirection));
352:     PetscCall(VecScale(lclP->r, -1.0));
353:     PetscCall(LCLGather(lclP, lclP->GAugL_U0, lclP->GAugL_V0, lclP->GAugL));
354:     PetscCall(LCLGather(lclP, lclP->U0, lclP->V0, lclP->X0));

356:     lclP->recompute_jacobian_flag = PETSC_TRUE;

358:     PetscCall(TaoLineSearchSetInitialStepLength(tao->linesearch, 1.0));
359:     PetscCall(TaoLineSearchSetType(tao->linesearch, TAOLINESEARCHMT));
360:     PetscCall(TaoLineSearchSetFromOptions(tao->linesearch));
361:     PetscCall(TaoLineSearchApply(tao->linesearch, tao->solution, &lclP->aug, lclP->GAugL, tao->stepdirection, &step, &ls_reason));
362:     if (lclP->verbose) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Steplength = %g\n", (double)step));

364:     PetscCall(LCLScatter(lclP, tao->solution, lclP->U, lclP->V));
365:     PetscCall(TaoComputeObjectiveAndGradient(tao, tao->solution, &f, tao->gradient));
366:     PetscCall(LCLScatter(lclP, tao->gradient, lclP->GU, lclP->GV));

368:     PetscCall(LCLScatter(lclP, lclP->GAugL, lclP->GAugL_U, lclP->GAugL_V));

370:     /* Check convergence */
371:     PetscCall(VecNorm(lclP->GAugL, NORM_2, &mnorm));
372:     PetscCall(VecNorm(tao->constraints, NORM_2, &cnorm));
373:     PetscCall(TaoLogConvergenceHistory(tao, f, mnorm, cnorm, tao->ksp_its));
374:     PetscCall(TaoMonitor(tao, tao->niter, f, mnorm, cnorm, step));
375:     PetscUseTypeMethod(tao, convergencetest, tao->cnvP);
376:     if (tao->reason != TAO_CONTINUE_ITERATING) break;

378:     /* TODO: use a heuristic to choose how many iterations should be performed within phase 2 */
379:     for (phase2_iter = 0; phase2_iter < lclP->phase2_niter; phase2_iter++) {
380:       /* We now minimize the objective function starting from the fraction of
381:          the Newton point accepted by applying one step of a reduced-space
382:          method.  The optimization problem is:

384:          minimize f(u+du, v+dv)
385:          s. t.    A(u0,v0)du + B(u0,v0)du = -alpha g(u0,v0)

387:          In particular, we have that
388:          du = -inv(A)*(Bdv + alpha g) */

390:       PetscCall(TaoComputeJacobianState(tao, lclP->X0, tao->jacobian_state, tao->jacobian_state_pre, tao->jacobian_state_inv));
391:       PetscCall(TaoComputeJacobianDesign(tao, lclP->X0, tao->jacobian_design));

393:       /* Store V and constraints */
394:       PetscCall(VecCopy(lclP->V, lclP->V1));
395:       PetscCall(VecCopy(tao->constraints, lclP->con1));

397:       /* Compute multipliers */
398:       /* p1 */
399:       PetscCall(VecSet(lclP->lambda, 0.0)); /*  Initial guess in CG */
400:       lclP->solve_type = LCL_ADJOINT1;
401:       PetscCall(MatIsSymmetricKnown(tao->jacobian_state, &set, &flag));
402:       if (tao->jacobian_state_pre) {
403:         PetscCall(MatIsSymmetricKnown(tao->jacobian_state_pre, &pset, &pflag));
404:       } else {
405:         pset = pflag = PETSC_TRUE;
406:       }
407:       if (set && pset && flag && pflag) symmetric = PETSC_TRUE;
408:       else symmetric = PETSC_FALSE;

410:       if (tao->jacobian_state_inv) {
411:         if (symmetric) {
412:           PetscCall(MatMult(tao->jacobian_state_inv, lclP->GAugL_U, lclP->lambda));
413:         } else {
414:           PetscCall(MatMultTranspose(tao->jacobian_state_inv, lclP->GAugL_U, lclP->lambda));
415:         }
416:       } else {
417:         if (symmetric) {
418:           PetscCall(KSPSolve(tao->ksp, lclP->GAugL_U, lclP->lambda));
419:         } else {
420:           PetscCall(KSPSolveTranspose(tao->ksp, lclP->GAugL_U, lclP->lambda));
421:         }
422:         PetscCall(KSPGetIterationNumber(tao->ksp, &its));
423:         tao->ksp_its += its;
424:         tao->ksp_tot_its += its;
425:       }
426:       PetscCall(MatMultTranspose(tao->jacobian_design, lclP->lambda, lclP->g1));
427:       PetscCall(VecAXPY(lclP->g1, -1.0, lclP->GAugL_V));

429:       /* Compute the limited-memory quasi-newton direction */
430:       if (tao->niter > 0) {
431:         PetscCall(MatSolve(lclP->R, lclP->g1, lclP->s));
432:         PetscCall(VecDot(lclP->s, lclP->g1, &descent));
433:         if (descent <= 0) {
434:           if (lclP->verbose) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Reduced-space direction not descent: %g\n", (double)descent));
435:           PetscCall(VecCopy(lclP->g1, lclP->s));
436:         }
437:       } else {
438:         PetscCall(VecCopy(lclP->g1, lclP->s));
439:       }
440:       PetscCall(VecScale(lclP->g1, -1.0));

442:       /* Recover the full space direction */
443:       PetscCall(MatMult(tao->jacobian_design, lclP->s, lclP->WU));
444:       /* PetscCall(VecSet(lclP->r,0.0)); */ /*  Initial guess in CG */
445:       lclP->solve_type = LCL_FORWARD2;
446:       if (tao->jacobian_state_inv) {
447:         PetscCall(MatMult(tao->jacobian_state_inv, lclP->WU, lclP->r));
448:       } else {
449:         PetscCall(KSPSolve(tao->ksp, lclP->WU, lclP->r));
450:         PetscCall(KSPGetIterationNumber(tao->ksp, &its));
451:         tao->ksp_its += its;
452:         tao->ksp_tot_its += its;
453:       }

455:       /* We now minimize the augmented Lagrangian along the direction -r,s */
456:       PetscCall(VecScale(lclP->r, -1.0));
457:       PetscCall(LCLGather(lclP, lclP->r, lclP->s, tao->stepdirection));
458:       PetscCall(VecScale(lclP->r, -1.0));
459:       lclP->recompute_jacobian_flag = PETSC_TRUE;

461:       PetscCall(TaoLineSearchSetInitialStepLength(tao->linesearch, 1.0));
462:       PetscCall(TaoLineSearchSetType(tao->linesearch, TAOLINESEARCHMT));
463:       PetscCall(TaoLineSearchSetFromOptions(tao->linesearch));
464:       PetscCall(TaoLineSearchApply(tao->linesearch, tao->solution, &lclP->aug, lclP->GAugL, tao->stepdirection, &step, &ls_reason));
465:       if (lclP->verbose) PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Reduced-space steplength =  %g\n", (double)step));

467:       PetscCall(LCLScatter(lclP, tao->solution, lclP->U, lclP->V));
468:       PetscCall(LCLScatter(lclP, lclP->GL, lclP->GL_U, lclP->GL_V));
469:       PetscCall(LCLScatter(lclP, lclP->GAugL, lclP->GAugL_U, lclP->GAugL_V));
470:       PetscCall(TaoComputeObjectiveAndGradient(tao, tao->solution, &f, tao->gradient));
471:       PetscCall(LCLScatter(lclP, tao->gradient, lclP->GU, lclP->GV));

473:       /* Compute the reduced gradient at the new point */

475:       PetscCall(TaoComputeJacobianState(tao, lclP->X0, tao->jacobian_state, tao->jacobian_state_pre, tao->jacobian_state_inv));
476:       PetscCall(TaoComputeJacobianDesign(tao, lclP->X0, tao->jacobian_design));

478:       /* p2 */
479:       /* Compute multipliers, using lambda-rho*con as an initial guess in PCG */
480:       if (phase2_iter == 0) {
481:         PetscCall(VecWAXPY(lclP->lambda, -lclP->rho, lclP->con1, lclP->lambda0));
482:       } else {
483:         PetscCall(VecAXPY(lclP->lambda, -lclP->rho, tao->constraints));
484:       }

486:       PetscCall(MatIsSymmetricKnown(tao->jacobian_state, &set, &flag));
487:       if (tao->jacobian_state_pre) {
488:         PetscCall(MatIsSymmetricKnown(tao->jacobian_state_pre, &pset, &pflag));
489:       } else {
490:         pset = pflag = PETSC_TRUE;
491:       }
492:       if (set && pset && flag && pflag) symmetric = PETSC_TRUE;
493:       else symmetric = PETSC_FALSE;

495:       lclP->solve_type = LCL_ADJOINT2;
496:       if (tao->jacobian_state_inv) {
497:         if (symmetric) {
498:           PetscCall(MatMult(tao->jacobian_state_inv, lclP->GU, lclP->lambda));
499:         } else {
500:           PetscCall(MatMultTranspose(tao->jacobian_state_inv, lclP->GU, lclP->lambda));
501:         }
502:       } else {
503:         if (symmetric) {
504:           PetscCall(KSPSolve(tao->ksp, lclP->GU, lclP->lambda));
505:         } else {
506:           PetscCall(KSPSolveTranspose(tao->ksp, lclP->GU, lclP->lambda));
507:         }
508:         PetscCall(KSPGetIterationNumber(tao->ksp, &its));
509:         tao->ksp_its += its;
510:         tao->ksp_tot_its += its;
511:       }

513:       PetscCall(MatMultTranspose(tao->jacobian_design, lclP->lambda, lclP->g2));
514:       PetscCall(VecAXPY(lclP->g2, -1.0, lclP->GV));

516:       PetscCall(VecScale(lclP->g2, -1.0));

518:       /* Update the quasi-newton approximation */
519:       PetscCall(MatLMVMUpdate(lclP->R, lclP->V, lclP->g2));
520:       /* Use "-tao_ls_type gpcg -tao_ls_ftol 0 -tao_lmm_broyden_phi 0.0 -tao_lmm_scale_type scalar" to obtain agreement with MATLAB code */
521:     }

523:     PetscCall(VecCopy(lclP->lambda, lclP->lambda0));

525:     /* Evaluate Function, Gradient, Constraints, and Jacobian */
526:     PetscCall(TaoComputeObjectiveAndGradient(tao, tao->solution, &f, tao->gradient));
527:     PetscCall(LCLScatter(lclP, tao->solution, lclP->U, lclP->V));
528:     PetscCall(LCLScatter(lclP, tao->gradient, lclP->GU, lclP->GV));

530:     PetscCall(TaoComputeJacobianState(tao, tao->solution, tao->jacobian_state, tao->jacobian_state_pre, tao->jacobian_state_inv));
531:     PetscCall(TaoComputeJacobianDesign(tao, tao->solution, tao->jacobian_design));
532:     PetscCall(TaoComputeConstraints(tao, tao->solution, tao->constraints));

534:     PetscCall(LCLComputeAugmentedLagrangianAndGradient(tao->linesearch, tao->solution, &lclP->aug, lclP->GAugL, tao));

536:     PetscCall(VecNorm(lclP->GAugL, NORM_2, &mnorm));

538:     /* Evaluate constraint norm */
539:     PetscCall(VecNorm(tao->constraints, NORM_2, &cnorm));

541:     /* Monitor convergence */
542:     tao->niter++;
543:     PetscCall(TaoLogConvergenceHistory(tao, f, mnorm, cnorm, tao->ksp_its));
544:     PetscCall(TaoMonitor(tao, tao->niter, f, mnorm, cnorm, step));
545:     PetscUseTypeMethod(tao, convergencetest, tao->cnvP);
546:   }
547:   PetscFunctionReturn(PETSC_SUCCESS);
548: }

550: /*MC
551:  TAOLCL - linearly constrained Lagrangian method for PDE-constrained optimization

553:  Option Database Keys:
554: + -tao_lcl_eps1         - epsilon 1 tolerance
555: . -tao_lcl_eps2         - epsilon 2 tolerance
556: . -tao_lcl_rho0         - initial value for rho
557: . -tao_lcl_rhomax       - maximum allowed value for rho
558: . -tao_lcl_phase2_niter - Number of phase 2 iterations in the LCL algorithm
559: . -tao_lcl_verbose      - Print verbose output if True
560: . -tao_lcl_tola         - Tolerance for first forward solve
561: . -tao_lcl_tolb         - Tolerance for first adjoint solve
562: . -tao_lcl_tolc         - Tolerance for second forward solve
563: - -tao_lcl_told         - Tolerance for second adjoint solve

565:   Level: beginner

567: .seealso: `Tao`, `TaoType`, `TaoSetStateDesignIS()`, `TaoSetJacobianStateRoutine()`, `TaoSetJacobianDesignRoutine()`
568: M*/
569: PETSC_EXTERN PetscErrorCode TaoCreate_LCL(Tao tao)
570: {
571:   TAO_LCL    *lclP;
572:   const char *morethuente_type = TAOLINESEARCHMT;

574:   PetscFunctionBegin;
575:   tao->ops->setup          = TaoSetup_LCL;
576:   tao->ops->solve          = TaoSolve_LCL;
577:   tao->ops->view           = TaoView_LCL;
578:   tao->ops->setfromoptions = TaoSetFromOptions_LCL;
579:   tao->ops->destroy        = TaoDestroy_LCL;
580:   PetscCall(PetscNew(&lclP));
581:   tao->data          = (void *)lclP;
582:   tao->uses_gradient = PETSC_TRUE;

584:   /* Override default settings (unless already changed) */
585:   PetscCall(TaoParametersInitialize(tao));
586:   PetscObjectParameterSetDefault(tao, max_it, 200);
587:   PetscObjectParameterSetDefault(tao, catol, 1.0e-4);
588:   PetscObjectParameterSetDefault(tao, gttol, 1.0e-4);
589:   PetscObjectParameterSetDefault(tao, gttol, 1.0e-4);
590:   PetscObjectParameterSetDefault(tao, gttol, 1.0e-4);

592:   lclP->rho0       = 1.0e-4;
593:   lclP->rhomax     = 1e5;
594:   lclP->eps1       = 1.0e-8;
595:   lclP->eps2       = 0.0;
596:   lclP->solve_type = 2;
597:   lclP->tau[0] = lclP->tau[1] = lclP->tau[2] = lclP->tau[3] = 1.0e-4;
598:   PetscCall(TaoLineSearchCreate(((PetscObject)tao)->comm, &tao->linesearch));
599:   PetscCall(PetscObjectIncrementTabLevel((PetscObject)tao->linesearch, (PetscObject)tao, 1));
600:   PetscCall(TaoLineSearchSetType(tao->linesearch, morethuente_type));
601:   PetscCall(TaoLineSearchSetOptionsPrefix(tao->linesearch, tao->hdr.prefix));

603:   PetscCall(TaoLineSearchSetObjectiveAndGradientRoutine(tao->linesearch, LCLComputeAugmentedLagrangianAndGradient, tao));
604:   PetscCall(KSPCreate(((PetscObject)tao)->comm, &tao->ksp));
605:   PetscCall(PetscObjectIncrementTabLevel((PetscObject)tao->ksp, (PetscObject)tao, 1));
606:   PetscCall(KSPSetOptionsPrefix(tao->ksp, tao->hdr.prefix));
607:   PetscCall(KSPSetFromOptions(tao->ksp));

609:   PetscCall(MatCreate(((PetscObject)tao)->comm, &lclP->R));
610:   PetscCall(MatSetType(lclP->R, MATLMVMBFGS));
611:   PetscFunctionReturn(PETSC_SUCCESS);
612: }

614: static PetscErrorCode LCLComputeLagrangianAndGradient(TaoLineSearch ls, Vec X, PetscReal *f, Vec G, void *ptr)
615: {
616:   Tao       tao  = (Tao)ptr;
617:   TAO_LCL  *lclP = (TAO_LCL *)tao->data;
618:   PetscBool set, pset, flag, pflag, symmetric;
619:   PetscReal cdotl;

621:   PetscFunctionBegin;
622:   PetscCall(TaoComputeObjectiveAndGradient(tao, X, f, G));
623:   PetscCall(LCLScatter(lclP, G, lclP->GU, lclP->GV));
624:   if (lclP->recompute_jacobian_flag) {
625:     PetscCall(TaoComputeJacobianState(tao, X, tao->jacobian_state, tao->jacobian_state_pre, tao->jacobian_state_inv));
626:     PetscCall(TaoComputeJacobianDesign(tao, X, tao->jacobian_design));
627:   }
628:   PetscCall(TaoComputeConstraints(tao, X, tao->constraints));
629:   PetscCall(MatIsSymmetricKnown(tao->jacobian_state, &set, &flag));
630:   if (tao->jacobian_state_pre) {
631:     PetscCall(MatIsSymmetricKnown(tao->jacobian_state_pre, &pset, &pflag));
632:   } else {
633:     pset = pflag = PETSC_TRUE;
634:   }
635:   if (set && pset && flag && pflag) symmetric = PETSC_TRUE;
636:   else symmetric = PETSC_FALSE;

638:   PetscCall(VecDot(lclP->lambda0, tao->constraints, &cdotl));
639:   lclP->lgn = *f - cdotl;

641:   /* Gradient of Lagrangian GL = G - J' * lambda */
642:   /*      WU = A' * WL
643:           WV = B' * WL */
644:   if (symmetric) {
645:     PetscCall(MatMult(tao->jacobian_state, lclP->lambda0, lclP->GL_U));
646:   } else {
647:     PetscCall(MatMultTranspose(tao->jacobian_state, lclP->lambda0, lclP->GL_U));
648:   }
649:   PetscCall(MatMultTranspose(tao->jacobian_design, lclP->lambda0, lclP->GL_V));
650:   PetscCall(VecScale(lclP->GL_U, -1.0));
651:   PetscCall(VecScale(lclP->GL_V, -1.0));
652:   PetscCall(VecAXPY(lclP->GL_U, 1.0, lclP->GU));
653:   PetscCall(VecAXPY(lclP->GL_V, 1.0, lclP->GV));
654:   PetscCall(LCLGather(lclP, lclP->GL_U, lclP->GL_V, lclP->GL));

656:   f[0] = lclP->lgn;
657:   PetscCall(VecCopy(lclP->GL, G));
658:   PetscFunctionReturn(PETSC_SUCCESS);
659: }

661: static PetscErrorCode LCLComputeAugmentedLagrangianAndGradient(TaoLineSearch ls, Vec X, PetscReal *f, Vec G, void *ptr)
662: {
663:   Tao       tao  = (Tao)ptr;
664:   TAO_LCL  *lclP = (TAO_LCL *)tao->data;
665:   PetscReal con2;
666:   PetscBool flag, pflag, set, pset, symmetric;

668:   PetscFunctionBegin;
669:   PetscCall(LCLComputeLagrangianAndGradient(tao->linesearch, X, f, G, tao));
670:   PetscCall(LCLScatter(lclP, G, lclP->GL_U, lclP->GL_V));
671:   PetscCall(VecDot(tao->constraints, tao->constraints, &con2));
672:   lclP->aug = lclP->lgn + 0.5 * lclP->rho * con2;

674:   /* Gradient of Aug. Lagrangian GAugL = GL + rho * J' c */
675:   /*      WU = A' * c
676:           WV = B' * c */
677:   PetscCall(MatIsSymmetricKnown(tao->jacobian_state, &set, &flag));
678:   if (tao->jacobian_state_pre) {
679:     PetscCall(MatIsSymmetricKnown(tao->jacobian_state_pre, &pset, &pflag));
680:   } else {
681:     pset = pflag = PETSC_TRUE;
682:   }
683:   if (set && pset && flag && pflag) symmetric = PETSC_TRUE;
684:   else symmetric = PETSC_FALSE;

686:   if (symmetric) {
687:     PetscCall(MatMult(tao->jacobian_state, tao->constraints, lclP->GAugL_U));
688:   } else {
689:     PetscCall(MatMultTranspose(tao->jacobian_state, tao->constraints, lclP->GAugL_U));
690:   }

692:   PetscCall(MatMultTranspose(tao->jacobian_design, tao->constraints, lclP->GAugL_V));
693:   PetscCall(VecAYPX(lclP->GAugL_U, lclP->rho, lclP->GL_U));
694:   PetscCall(VecAYPX(lclP->GAugL_V, lclP->rho, lclP->GL_V));
695:   PetscCall(LCLGather(lclP, lclP->GAugL_U, lclP->GAugL_V, lclP->GAugL));

697:   f[0] = lclP->aug;
698:   PetscCall(VecCopy(lclP->GAugL, G));
699:   PetscFunctionReturn(PETSC_SUCCESS);
700: }

702: static PetscErrorCode LCLGather(TAO_LCL *lclP, Vec u, Vec v, Vec x)
703: {
704:   PetscFunctionBegin;
705:   PetscCall(VecScatterBegin(lclP->state_scatter, u, x, INSERT_VALUES, SCATTER_REVERSE));
706:   PetscCall(VecScatterEnd(lclP->state_scatter, u, x, INSERT_VALUES, SCATTER_REVERSE));
707:   PetscCall(VecScatterBegin(lclP->design_scatter, v, x, INSERT_VALUES, SCATTER_REVERSE));
708:   PetscCall(VecScatterEnd(lclP->design_scatter, v, x, INSERT_VALUES, SCATTER_REVERSE));
709:   PetscFunctionReturn(PETSC_SUCCESS);
710: }
711: static PetscErrorCode LCLScatter(TAO_LCL *lclP, Vec x, Vec u, Vec v)
712: {
713:   PetscFunctionBegin;
714:   PetscCall(VecScatterBegin(lclP->state_scatter, x, u, INSERT_VALUES, SCATTER_FORWARD));
715:   PetscCall(VecScatterEnd(lclP->state_scatter, x, u, INSERT_VALUES, SCATTER_FORWARD));
716:   PetscCall(VecScatterBegin(lclP->design_scatter, x, v, INSERT_VALUES, SCATTER_FORWARD));
717:   PetscCall(VecScatterEnd(lclP->design_scatter, x, v, INSERT_VALUES, SCATTER_FORWARD));
718:   PetscFunctionReturn(PETSC_SUCCESS);
719: }