Actual source code: bnls.c

  1: /*$Id: s.bnls.c 1.128 02/08/16 18:01:18-05:00 benson@rockies.mcs.anl.gov $*/

  3: #include "bnls.h"       /*I "tao_solver.h" I*/



  9: static int TaoSolve_BNLS(TAO_SOLVER tao, void*solver){

 11:   TAO_BNLS *bnls = (TAO_BNLS *)solver;
 12:   int info,lsflag,iter=0;
 13:   TaoTerminateReason reason=TAO_CONTINUE_ITERATING;
 14:   double f,f_full,gnorm,gdx,stepsize=1.0;
 15:   TaoTruth success;
 16:   TaoVec *XU, *XL;
 17:   TaoVec *X,  *G=bnls->G, *PG=bnls->PG;
 18:   TaoVec *R=bnls->R, *DXFree=bnls->DXFree;
 19:   TaoVec *DX=bnls->DX, *Work=bnls->Work;
 20:   TaoMat *H, *Hsub=bnls->Hsub;
 21:   TaoIndexSet *FreeVariables = bnls->FreeVariables;

 23:   TaoFunctionBegin;

 25:   /* Check if upper bound greater than lower bound. */
 26:   info = TaoGetSolution(tao,&X);CHKERRQ(info); bnls->X=X;
 27:   info = TaoGetVariableBounds(tao,&XL,&XU);CHKERRQ(info);
 28:   info = TaoEvaluateVariableBounds(tao,XL,XU); CHKERRQ(info);
 29:   info = TaoGetHessian(tao,&H);CHKERRQ(info); bnls->H=H;

 31:   /*   Project the current point onto the feasible set */
 32:   info = X->Median(XL,X,XU); CHKERRQ(info);
 33:   
 34:   info = TaoComputeMeritFunctionGradient(tao,X,&f,G);CHKERRQ(info);
 35:   
 36:   while (reason==TAO_CONTINUE_ITERATING){
 37:     
 38:     /* Project the gradient and calculate the norm */
 39:     info = PG->BoundGradientProjection(G,XL,X,XU);CHKERRQ(info);
 40:     info = PG->Norm2(&gnorm); CHKERRQ(info);
 41:     
 42:     info = TaoMonitor(tao,iter++,f,gnorm,0.0,stepsize,&reason);
 43:     CHKERRQ(info);
 44:     if (reason!=TAO_CONTINUE_ITERATING) break;

 46:     info = FreeVariables->WhichEqual(PG,G); CHKERRQ(info);

 48:     info = TaoComputeHessian(tao,X,H);CHKERRQ(info);
 49:     
 50:     /* Create a reduced linear system */

 52:     info = R->SetReducedVec(G,FreeVariables);CHKERRQ(info);
 53:     info = R->Negate();CHKERRQ(info);

 55:     info = DXFree->SetReducedVec(DX,FreeVariables);CHKERRQ(info);
 56:     info = DXFree->SetToZero(); CHKERRQ(info);
 57:     
 58:     info = Hsub->SetReducedMatrix(H,FreeVariables,FreeVariables);CHKERRQ(info);

 60:     bnls->gamma_factor /= 2;
 61:     success = TAO_FALSE;

 63:     while (success==TAO_FALSE) {
 64:       
 65:       /* Approximately solve the reduced linear system */
 66:       info = TaoPreLinearSolve(tao,Hsub);CHKERRQ(info);
 67:       info = TaoLinearSolve(tao,Hsub,R,DXFree,&success);CHKERRQ(info);

 69:       info = DX->SetToZero(); CHKERRQ(info);
 70:       info = DX->ReducedXPY(DXFree,FreeVariables);CHKERRQ(info);
 71:       info = DX->Dot(G,&gdx); CHKERRQ(info);

 73:       if (gdx>=0 || success==TAO_FALSE) { /* Modify diagonal of Hessian if not a descent direction */
 74:         bnls->gamma_factor *= 2; 
 75:         bnls->gamma = bnls->gamma_factor*(gnorm); 
 76: #if !defined(PETSC_USE_COMPLEX)
 77:         info=PetscInfo2(tao,"TaoSolve_NLS:  modify diagonal (assume same nonzero structure), gamma_factor=%g, gamma=%g\n",bnls->gamma_factor,bnls->gamma);
 78:         CHKERRQ(info);
 79: #else
 80:         info=PetscInfo3(tao,"TaoSolve_NLS:  modify diagonal (asuume same nonzero structure), gamma_factor=%g, gamma=%g\n",
 81:              bnls->gamma_factor,PetscReal(bnls->gamma));CHKERRQ(info);
 82: #endif
 83:         info = Hsub->ShiftDiagonal(bnls->gamma);CHKERRQ(info);
 84:         success = TAO_FALSE;
 85:         
 86:       } else {
 87:         success = TAO_TRUE;
 88:       }

 90:     }
 91:     
 92:     stepsize=1.0;        
 93:     info = TaoLineSearchApply(tao,X,G,DX,Work,
 94:                               &f,&f_full,&stepsize,&lsflag);
 95:     CHKERRQ(info);

 97:     
 98:   }  /* END MAIN LOOP  */

100:   TaoFunctionReturn(0);
101: }


104: /*------------------------------------------------------------*/
107: static int TaoSetDown_BNLS(TAO_SOLVER tao, void*solver)
108: {
109:   TAO_BNLS *bnls = (TAO_BNLS *)solver;
110:   int      info;
111:   /* Free allocated memory in BNLS structure */
112:   TaoFunctionBegin;
113:   
114:   info = TaoVecDestroy(bnls->DX);CHKERRQ(info);bnls->DX=0;
115:   info = TaoVecDestroy(bnls->Work);CHKERRQ(info);
116:   info = TaoVecDestroy(bnls->DXFree);CHKERRQ(info);
117:   info = TaoVecDestroy(bnls->R);CHKERRQ(info);
118:   info = TaoVecDestroy(bnls->G);CHKERRQ(info);
119:   info = TaoVecDestroy(bnls->PG);CHKERRQ(info);
120:   info = TaoVecDestroy(bnls->XL);CHKERRQ(info);
121:   info = TaoVecDestroy(bnls->XU);CHKERRQ(info);
122:   
123:   info = TaoIndexSetDestroy(bnls->FreeVariables);CHKERRQ(info);
124:   info = TaoMatDestroy(bnls->Hsub);CHKERRQ(info);
125:   info = TaoDestroyLinearSolver(tao);CHKERRQ(info);

127:   TaoFunctionReturn(0);
128: }

130: /*------------------------------------------------------------*/
133: static int TaoSetOptions_BNLS(TAO_SOLVER tao, void*solver)
134: {
135:   int        info,ival;
136:   TaoTruth flg;

138:   TaoFunctionBegin;

140:   info = TaoOptionsHead("Newton Line Search Method for bound constrained optimization");CHKERRQ(info);

142:   info = TaoOptionInt("-redistribute","Redistribute Free variables (> 1 processors, only)","TaoPetscISType",1,&ival,&flg); CHKERRQ(info);

144:   info = TaoOptionName("-submatrixfree","Mask full matrix instead of extract submatrices","TaoPetscISType",&flg); CHKERRQ(info);

146:   info = TaoOptionsTail();CHKERRQ(info);
147:   info = TaoLineSearchSetFromOptions(tao);CHKERRQ(info);

149:   TaoFunctionReturn(0);
150: }

152: /*------------------------------------------------------------*/
155: static int TaoView_BNLS(TAO_SOLVER tao,void*solver)
156: {
157:   int        info;

159:   TaoFunctionBegin;
160:   info = TaoLineSearchView(tao);CHKERRQ(info);
161:   TaoFunctionReturn(0);
162: }


165: /* ---------------------------------------------------------- */
168: static int TaoSetUp_BNLS(TAO_SOLVER tao, void*solver){

170:   int info;
171:   TAO_BNLS *bnls = (TAO_BNLS *)solver;
172:   TaoVec* X;
173:   TaoMat *HH;

175:   TaoFunctionBegin;
176:   info = TaoGetSolution(tao,&bnls->X);CHKERRQ(info); X=bnls->X;
177:   info = TaoGetHessian(tao,&bnls->H);CHKERRQ(info);  HH=bnls->H;

179:   /* Allocate some arrays */
180:   info = X->Clone(&bnls->DX); CHKERRQ(info);
181:   info = X->Clone(&bnls->Work); CHKERRQ(info);
182:   info = X->Clone(&bnls->DXFree); CHKERRQ(info);
183:   info = X->Clone(&bnls->R); CHKERRQ(info);
184:   info = X->Clone(&bnls->G); CHKERRQ(info);
185:   info = X->Clone(&bnls->PG); CHKERRQ(info);
186:   info = X->Clone(&bnls->XL); CHKERRQ(info);
187:   info = X->Clone(&bnls->XU); CHKERRQ(info);

189:   info = TaoSetLagrangianGradientVector(tao,bnls->PG);CHKERRQ(info);
190:   info = TaoSetStepDirectionVector(tao,bnls->DX);CHKERRQ(info);
191:   info = TaoSetVariableBounds(tao,bnls->XL,bnls->XU);CHKERRQ(info);

193:   info = X->CreateIndexSet(&bnls->FreeVariables); CHKERRQ(info);
194:   info = bnls->H->CreateReducedMatrix(bnls->FreeVariables,bnls->FreeVariables,&bnls->Hsub); CHKERRQ(info);

196:   info = TaoCreateLinearSolver(tao,HH,100,0); CHKERRQ(info);

198:   info = TaoCheckFGH(tao);CHKERRQ(info);

200:   TaoFunctionReturn(0);
201: }

203: /*------------------------------------------------------------*/
206: int TaoGetDualVariables_BNLS(TAO_SOLVER tao, TaoVec* DXL, TaoVec* DXU, void* solver)
207: {

209:   TAO_BNLS *bnls = (TAO_BNLS *) solver;
210:   TaoVec  *G=bnls->G,*GP=bnls->Work;
211:   int       info;

213:   TaoFunctionBegin;

215:   info = DXL->Waxpby(-1,G,1.0,GP); CHKERRQ(info);
216:   info = DXU->SetToZero(); CHKERRQ(info);
217:   info = DXL->PointwiseMaximum(DXL,DXU); CHKERRQ(info);

219:   info = DXU->Waxpby(-1.0,GP,1.0,G); CHKERRQ(info);
220:   info = DXU->Axpy(1.0,DXL); CHKERRQ(info);

222:   TaoFunctionReturn(0);
223: }


226: /*------------------------------------------------------------*/
230: int TaoCreate_BNLS(TAO_SOLVER tao)
231: {
232:   TAO_BNLS *bnls;
233:   int      info;

235:   TaoFunctionBegin;

237:   info = TaoNew(TAO_BNLS,&bnls); CHKERRQ(info);
238:   info = PetscLogObjectMemory(tao,sizeof(TAO_BNLS)); CHKERRQ(info);

240:   info=TaoSetTaoSolveRoutine(tao,TaoSolve_BNLS,(void*)bnls); CHKERRQ(info);
241:   info=TaoSetTaoSetUpDownRoutines(tao,TaoSetUp_BNLS,TaoSetDown_BNLS); CHKERRQ(info);
242:   info=TaoSetTaoOptionsRoutine(tao,TaoSetOptions_BNLS); CHKERRQ(info);
243:   info=TaoSetTaoViewRoutine(tao,TaoView_BNLS); CHKERRQ(info);
244:   info=TaoSetTaoDualVariablesRoutine(tao,TaoGetDualVariables_BNLS); CHKERRQ(info);

246:   info = TaoSetMaximumIterates(tao,500); CHKERRQ(info);
247:   info = TaoSetTolerances(tao,1e-12,1e-12,0,0); CHKERRQ(info);

249:   /* Initialize pointers and variables */

251:   bnls->gamma = 0.0;
252:   bnls->gamma_factor = 0.01;
253:   bnls->DX=0;
254:   bnls->DXFree=0;
255:   bnls->R=0;
256:   bnls->Work=0;
257:   bnls->FreeVariables=0;
258:   bnls->Hsub=0;

260:   info = TaoCreateMoreThuenteBoundLineSearch(tao,0,0.9); CHKERRQ(info);

262:   TaoFunctionReturn(0);
263: }