Date: 2022-03-31T04:48:54+00:00

Actual source code: ex1.c

      1: #include <petsctao.h>
      2: #include <petscts.h>

      4: typedef struct _n_aircraft *Aircraft;
      5: struct _n_aircraft {
      6:   TS        ts,quadts;
      7:   Vec       V,W;    /* control variables V and W */
      8:   PetscInt  nsteps; /* number of time steps */
      9:   PetscReal ftime;
     10:   Mat       A,H;
     11:   Mat       Jacp,DRDU,DRDP;
     12:   Vec       U,Lambda[1],Mup[1],Lambda2[1],Mup2[1],Dir;
     13:   Vec       rhshp1[1],rhshp2[1],rhshp3[1],rhshp4[1],inthp1[1],inthp2[1],inthp3[1],inthp4[1];
     14:   PetscReal lv,lw;
     15:   PetscBool mf,eh;
     16: };

     18: PetscErrorCode FormObjFunctionGradient(Tao,Vec,PetscReal *,Vec,void *);
     19: PetscErrorCode FormObjHessian(Tao,Vec,Mat,Mat,void *);
     20: PetscErrorCode ComputeObjHessianWithSOA(Vec,PetscScalar[],Aircraft);
     21: PetscErrorCode MatrixFreeObjHessian(Tao,Vec,Mat,Mat,void *);
     22: PetscErrorCode MyMatMult(Mat,Vec,Vec);

     24: static PetscErrorCode RHSFunction(TS ts,PetscReal t,Vec U,Vec F,void *ctx)
     25: {
     26:   Aircraft          actx = (Aircraft)ctx;
     27:   const PetscScalar *u,*v,*w;
     28:   PetscScalar       *f;
     29:   PetscInt          step;

     32:   TSGetStepNumber(ts,&step);
     33:   VecGetArrayRead(U,&u);
     34:   VecGetArrayRead(actx->V,&v);
     35:   VecGetArrayRead(actx->W,&w);
     36:   VecGetArray(F,&f);
     37:   f[0] = v[step]*PetscCosReal(w[step]);
     38:   f[1] = v[step]*PetscSinReal(w[step]);
     39:   VecRestoreArrayRead(U,&u);
     40:   VecRestoreArrayRead(actx->V,&v);
     41:   VecRestoreArrayRead(actx->W,&w);
     42:   VecRestoreArray(F,&f);
     43:   return 0;
     44: }

     46: static PetscErrorCode RHSJacobianP(TS ts,PetscReal t,Vec U,Mat A,void *ctx)
     47: {
     48:   Aircraft          actx = (Aircraft)ctx;
     49:   const PetscScalar *u,*v,*w;
     50:   PetscInt          step,rows[2] = {0,1},rowcol[2];
     51:   PetscScalar       Jp[2][2];

     54:   MatZeroEntries(A);
     55:   TSGetStepNumber(ts,&step);
     56:   VecGetArrayRead(U,&u);
     57:   VecGetArrayRead(actx->V,&v);
     58:   VecGetArrayRead(actx->W,&w);

     60:   Jp[0][0] = PetscCosReal(w[step]);
     61:   Jp[0][1] = -v[step]*PetscSinReal(w[step]);
     62:   Jp[1][0] = PetscSinReal(w[step]);
     63:   Jp[1][1] = v[step]*PetscCosReal(w[step]);

     65:   VecRestoreArrayRead(U,&u);
     66:   VecRestoreArrayRead(actx->V,&v);
     67:   VecRestoreArrayRead(actx->W,&w);

     69:   rowcol[0] = 2*step;
     70:   rowcol[1] = 2*step+1;
     71:   MatSetValues(A,2,rows,2,rowcol,&Jp[0][0],INSERT_VALUES);

     73:   MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
     74:   MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
     75:   return 0;
     76: }

     78: static PetscErrorCode RHSHessianProductUU(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
     79: {
     81:   return 0;
     82: }

     84: static PetscErrorCode RHSHessianProductUP(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
     85: {
     87:   return 0;
     88: }

     90: static PetscErrorCode RHSHessianProductPU(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
     91: {
     93:   return 0;
     94: }

     96: static PetscErrorCode RHSHessianProductPP(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
     97: {
     98:   Aircraft          actx = (Aircraft)ctx;
     99:   const PetscScalar *v,*w,*vl,*vr,*u;
    100:   PetscScalar       *vhv;
    101:   PetscScalar       dJpdP[2][2][2]={{{0}}};
    102:   PetscInt          step,i,j,k;

    105:   TSGetStepNumber(ts,&step);
    106:   VecGetArrayRead(U,&u);
    107:   VecGetArrayRead(actx->V,&v);
    108:   VecGetArrayRead(actx->W,&w);
    109:   VecGetArrayRead(Vl[0],&vl);
    110:   VecGetArrayRead(Vr,&vr);
    111:   VecSet(VHV[0],0.0);
    112:   VecGetArray(VHV[0],&vhv);

    114:   dJpdP[0][0][1] = -PetscSinReal(w[step]);
    115:   dJpdP[0][1][0] = -PetscSinReal(w[step]);
    116:   dJpdP[0][1][1] = -v[step]*PetscCosReal(w[step]);
    117:   dJpdP[1][0][1] = PetscCosReal(w[step]);
    118:   dJpdP[1][1][0] = PetscCosReal(w[step]);
    119:   dJpdP[1][1][1] = -v[step]*PetscSinReal(w[step]);

    121:   for (j=0; j<2; j++) {
    122:     vhv[2*step+j] = 0;
    123:     for (k=0; k<2; k++)
    124:       for (i=0; i<2; i++)
    125:         vhv[2*step+j] += vl[i]*dJpdP[i][j][k]*vr[2*step+k];
    126:   }
    127:   VecRestoreArrayRead(U,&u);
    128:   VecRestoreArrayRead(Vl[0],&vl);
    129:   VecRestoreArrayRead(Vr,&vr);
    130:   VecRestoreArray(VHV[0],&vhv);
    131:   return 0;
    132: }

    134: /* Vl in NULL,updates to VHV must be added */
    135: static PetscErrorCode IntegrandHessianProductUU(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
    136: {
    137:   Aircraft          actx = (Aircraft)ctx;
    138:   const PetscScalar *v,*w,*vr,*u;
    139:   PetscScalar       *vhv;
    140:   PetscScalar       dRudU[2][2]={{0}};
    141:   PetscInt          step,j,k;

    144:   TSGetStepNumber(ts,&step);
    145:   VecGetArrayRead(U,&u);
    146:   VecGetArrayRead(actx->V,&v);
    147:   VecGetArrayRead(actx->W,&w);
    148:   VecGetArrayRead(Vr,&vr);
    149:   VecGetArray(VHV[0],&vhv);

    151:   dRudU[0][0] = 2.0;
    152:   dRudU[1][1] = 2.0;

    154:   for (j=0; j<2; j++) {
    155:     vhv[j] = 0;
    156:     for (k=0; k<2; k++)
    157:         vhv[j] += dRudU[j][k]*vr[k];
    158:   }
    159:   VecRestoreArrayRead(U,&u);
    160:   VecRestoreArrayRead(Vr,&vr);
    161:   VecRestoreArray(VHV[0],&vhv);
    162:   return 0;
    163: }

    165: static PetscErrorCode IntegrandHessianProductUP(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
    166: {
    168:   return 0;
    169: }

    171: static PetscErrorCode IntegrandHessianProductPU(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
    172: {
    174:   return 0;
    175: }

    177: static PetscErrorCode IntegrandHessianProductPP(TS ts,PetscReal t,Vec U,Vec *Vl,Vec Vr,Vec *VHV,void *ctx)
    178: {
    180:   return 0;
    181: }

    183: static PetscErrorCode CostIntegrand(TS ts,PetscReal t,Vec U,Vec R,void *ctx)
    184: {
    185:   Aircraft          actx = (Aircraft)ctx;
    186:   PetscScalar       *r;
    187:   PetscReal         dx,dy;
    188:   const PetscScalar *u;

    190:   VecGetArrayRead(U,&u);
    191:   VecGetArray(R,&r);
    192:   dx   = u[0] - actx->lv*t*PetscCosReal(actx->lw);
    193:   dy   = u[1] - actx->lv*t*PetscSinReal(actx->lw);
    194:   r[0] = dx*dx+dy*dy;
    195:   VecRestoreArray(R,&r);
    196:   VecRestoreArrayRead(U,&u);
    197:   return 0;
    198: }

    200: static PetscErrorCode DRDUJacobianTranspose(TS ts,PetscReal t,Vec U,Mat DRDU,Mat B,void *ctx)
    201: {
    202:   Aircraft          actx = (Aircraft)ctx;
    203:   PetscScalar       drdu[2][1];
    204:   const PetscScalar *u;
    205:   PetscReal         dx,dy;
    206:   PetscInt          row[] = {0,1},col[] = {0};

    208:   VecGetArrayRead(U,&u);
    209:   dx      = u[0] - actx->lv*t*PetscCosReal(actx->lw);
    210:   dy      = u[1] - actx->lv*t*PetscSinReal(actx->lw);
    211:   drdu[0][0] = 2.*dx;
    212:   drdu[1][0] = 2.*dy;
    213:   MatSetValues(DRDU,2,row,1,col,&drdu[0][0],INSERT_VALUES);
    214:   VecRestoreArrayRead(U,&u);
    215:   MatAssemblyBegin(DRDU,MAT_FINAL_ASSEMBLY);
    216:   MatAssemblyEnd(DRDU,MAT_FINAL_ASSEMBLY);
    217:   return 0;
    218: }

    220: static PetscErrorCode DRDPJacobianTranspose(TS ts,PetscReal t,Vec U,Mat DRDP,void *ctx)
    221: {
    222:   MatZeroEntries(DRDP);
    223:   MatAssemblyBegin(DRDP,MAT_FINAL_ASSEMBLY);
    224:   MatAssemblyEnd(DRDP,MAT_FINAL_ASSEMBLY);
    225:   return 0;
    226: }

    228: int main(int argc,char **argv)
    229: {
    230:   Vec                P,PL,PU;
    231:   struct _n_aircraft aircraft;
    232:   PetscMPIInt        size;
    233:   Tao                tao;
    234:   KSP                ksp;
    235:   PC                 pc;
    236:   PetscScalar        *u,*p;
    237:   PetscInt           i;

    239:   /* Initialize program */
    240:   PetscInitialize(&argc,&argv,NULL,NULL);
    241:   MPI_Comm_size(PETSC_COMM_WORLD,&size);

    244:   /* Parameter settings */
    245:   aircraft.ftime = 1.;   /* time interval in hour */
    246:   aircraft.nsteps = 10; /* number of steps */
    247:   aircraft.lv = 2.0; /* leader speed in kmph */
    248:   aircraft.lw = PETSC_PI/4.; /* leader heading angle */

    250:   PetscOptionsGetReal(NULL,NULL,"-ftime",&aircraft.ftime,NULL);
    251:   PetscOptionsGetInt(NULL,NULL,"-nsteps",&aircraft.nsteps,NULL);
    252:   PetscOptionsHasName(NULL,NULL,"-matrixfree",&aircraft.mf);
    253:   PetscOptionsHasName(NULL,NULL,"-exacthessian",&aircraft.eh);

    255:   /* Create TAO solver and set desired solution method */
    256:   TaoCreate(PETSC_COMM_WORLD,&tao);
    257:   TaoSetType(tao,TAOBQNLS);

    259:   /* Create necessary matrix and vectors, solve same ODE on every process */
    260:   MatCreate(PETSC_COMM_WORLD,&aircraft.A);
    261:   MatSetSizes(aircraft.A,PETSC_DECIDE,PETSC_DECIDE,2,2);
    262:   MatSetFromOptions(aircraft.A);
    263:   MatSetUp(aircraft.A);
    264:   MatAssemblyBegin(aircraft.A,MAT_FINAL_ASSEMBLY);
    265:   MatAssemblyEnd(aircraft.A,MAT_FINAL_ASSEMBLY);
    266:   MatShift(aircraft.A,1);
    267:   MatShift(aircraft.A,-1);

    269:   MatCreate(PETSC_COMM_WORLD,&aircraft.Jacp);
    270:   MatSetSizes(aircraft.Jacp,PETSC_DECIDE,PETSC_DECIDE,2,2*aircraft.nsteps);
    271:   MatSetFromOptions(aircraft.Jacp);
    272:   MatSetUp(aircraft.Jacp);
    273:   MatCreateDense(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,2*aircraft.nsteps,1,NULL,&aircraft.DRDP);
    274:   MatSetUp(aircraft.DRDP);
    275:   MatCreateDense(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,2,1,NULL,&aircraft.DRDU);
    276:   MatSetUp(aircraft.DRDU);

    278:   /* Create timestepping solver context */
    279:   TSCreate(PETSC_COMM_WORLD,&aircraft.ts);
    280:   TSSetType(aircraft.ts,TSRK);
    281:   TSSetRHSFunction(aircraft.ts,NULL,RHSFunction,&aircraft);
    282:   TSSetRHSJacobian(aircraft.ts,aircraft.A,aircraft.A,TSComputeRHSJacobianConstant,&aircraft);
    283:   TSSetRHSJacobianP(aircraft.ts,aircraft.Jacp,RHSJacobianP,&aircraft);
    284:   TSSetExactFinalTime(aircraft.ts,TS_EXACTFINALTIME_MATCHSTEP);
    285:   TSSetEquationType(aircraft.ts,TS_EQ_ODE_EXPLICIT); /* less Jacobian evaluations when adjoint BEuler is used, otherwise no effect */

    287:   /* Set initial conditions */
    288:   MatCreateVecs(aircraft.A,&aircraft.U,NULL);
    289:   TSSetSolution(aircraft.ts,aircraft.U);
    290:   VecGetArray(aircraft.U,&u);
    291:   u[0] = 1.5;
    292:   u[1] = 0;
    293:   VecRestoreArray(aircraft.U,&u);
    294:   VecCreate(PETSC_COMM_WORLD,&aircraft.V);
    295:   VecSetSizes(aircraft.V,PETSC_DECIDE,aircraft.nsteps);
    296:   VecSetUp(aircraft.V);
    297:   VecDuplicate(aircraft.V,&aircraft.W);
    298:   VecSet(aircraft.V,1.);
    299:   VecSet(aircraft.W,PETSC_PI/4.);

    301:   /* Save trajectory of solution so that TSAdjointSolve() may be used */
    302:   TSSetSaveTrajectory(aircraft.ts);

    304:   /* Set sensitivity context */
    305:   TSCreateQuadratureTS(aircraft.ts,PETSC_FALSE,&aircraft.quadts);
    306:   TSSetRHSFunction(aircraft.quadts,NULL,(TSRHSFunction)CostIntegrand,&aircraft);
    307:   TSSetRHSJacobian(aircraft.quadts,aircraft.DRDU,aircraft.DRDU,(TSRHSJacobian)DRDUJacobianTranspose,&aircraft);
    308:   TSSetRHSJacobianP(aircraft.quadts,aircraft.DRDP,(TSRHSJacobianP)DRDPJacobianTranspose,&aircraft);
    309:   MatCreateVecs(aircraft.A,&aircraft.Lambda[0],NULL);
    310:   MatCreateVecs(aircraft.Jacp,&aircraft.Mup[0],NULL);
    311:   if (aircraft.eh) {
    312:     MatCreateVecs(aircraft.A,&aircraft.rhshp1[0],NULL);
    313:     MatCreateVecs(aircraft.A,&aircraft.rhshp2[0],NULL);
    314:     MatCreateVecs(aircraft.Jacp,&aircraft.rhshp3[0],NULL);
    315:     MatCreateVecs(aircraft.Jacp,&aircraft.rhshp4[0],NULL);
    316:     MatCreateVecs(aircraft.DRDU,&aircraft.inthp1[0],NULL);
    317:     MatCreateVecs(aircraft.DRDU,&aircraft.inthp2[0],NULL);
    318:     MatCreateVecs(aircraft.DRDP,&aircraft.inthp3[0],NULL);
    319:     MatCreateVecs(aircraft.DRDP,&aircraft.inthp4[0],NULL);
    320:     MatCreateVecs(aircraft.Jacp,&aircraft.Dir,NULL);
    321:     TSSetRHSHessianProduct(aircraft.ts,aircraft.rhshp1,RHSHessianProductUU,aircraft.rhshp2,RHSHessianProductUP,aircraft.rhshp3,RHSHessianProductPU,aircraft.rhshp4,RHSHessianProductPP,&aircraft);
    322:     TSSetRHSHessianProduct(aircraft.quadts,aircraft.inthp1,IntegrandHessianProductUU,aircraft.inthp2,IntegrandHessianProductUP,aircraft.inthp3,IntegrandHessianProductPU,aircraft.inthp4,IntegrandHessianProductPP,&aircraft);
    323:     MatCreateVecs(aircraft.A,&aircraft.Lambda2[0],NULL);
    324:     MatCreateVecs(aircraft.Jacp,&aircraft.Mup2[0],NULL);
    325:   }
    326:   TSSetFromOptions(aircraft.ts);
    327:   TSSetMaxTime(aircraft.ts,aircraft.ftime);
    328:   TSSetTimeStep(aircraft.ts,aircraft.ftime/aircraft.nsteps);

    330:   /* Set initial solution guess */
    331:   MatCreateVecs(aircraft.Jacp,&P,NULL);
    332:   VecGetArray(P,&p);
    333:   for (i=0; i<aircraft.nsteps; i++) {
    334:     p[2*i] = 2.0;
    335:     p[2*i+1] = PETSC_PI/2.0;
    336:   }
    337:   VecRestoreArray(P,&p);
    338:   VecDuplicate(P,&PU);
    339:   VecDuplicate(P,&PL);
    340:   VecGetArray(PU,&p);
    341:   for (i=0; i<aircraft.nsteps; i++) {
    342:     p[2*i] = 2.0;
    343:     p[2*i+1] = PETSC_PI;
    344:   }
    345:   VecRestoreArray(PU,&p);
    346:   VecGetArray(PL,&p);
    347:   for (i=0; i<aircraft.nsteps; i++) {
    348:     p[2*i] = 0.0;
    349:     p[2*i+1] = -PETSC_PI;
    350:   }
    351:   VecRestoreArray(PL,&p);

    353:   TaoSetSolution(tao,P);
    354:   TaoSetVariableBounds(tao,PL,PU);
    355:   /* Set routine for function and gradient evaluation */
    356:   TaoSetObjectiveAndGradient(tao,NULL,FormObjFunctionGradient,(void *)&aircraft);

    358:   if (aircraft.eh) {
    359:     if (aircraft.mf) {
    360:       MatCreateShell(PETSC_COMM_WORLD,PETSC_DECIDE,PETSC_DECIDE,2*aircraft.nsteps,2*aircraft.nsteps,(void*)&aircraft,&aircraft.H);
    361:       MatShellSetOperation(aircraft.H,MATOP_MULT,(void(*)(void))MyMatMult);
    362:       MatSetOption(aircraft.H,MAT_SYMMETRIC,PETSC_TRUE);
    363:       TaoSetHessian(tao,aircraft.H,aircraft.H,MatrixFreeObjHessian,(void*)&aircraft);
    364:     } else {
    365:       MatCreateDense(MPI_COMM_WORLD,PETSC_DETERMINE,PETSC_DETERMINE,2*aircraft.nsteps,2*aircraft.nsteps,NULL,&(aircraft.H));
    366:       MatSetOption(aircraft.H,MAT_SYMMETRIC,PETSC_TRUE);
    367:       TaoSetHessian(tao,aircraft.H,aircraft.H,FormObjHessian,(void *)&aircraft);
    368:     }
    369:   }

    371:   /* Check for any TAO command line options */
    372:   TaoGetKSP(tao,&ksp);
    373:   if (ksp) {
    374:     KSPGetPC(ksp,&pc);
    375:     PCSetType(pc,PCNONE);
    376:   }
    377:   TaoSetFromOptions(tao);

    379:   TaoSolve(tao);
    380:   VecView(P,PETSC_VIEWER_STDOUT_WORLD);

    382:   /* Free TAO data structures */
    383:   TaoDestroy(&tao);

    385:   /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
    386:      Free work space.  All PETSc objects should be destroyed when they
    387:      are no longer needed.
    388:    - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
    389:   TSDestroy(&aircraft.ts);
    390:   MatDestroy(&aircraft.A);
    391:   VecDestroy(&aircraft.U);
    392:   VecDestroy(&aircraft.V);
    393:   VecDestroy(&aircraft.W);
    394:   VecDestroy(&P);
    395:   VecDestroy(&PU);
    396:   VecDestroy(&PL);
    397:   MatDestroy(&aircraft.Jacp);
    398:   MatDestroy(&aircraft.DRDU);
    399:   MatDestroy(&aircraft.DRDP);
    400:   VecDestroy(&aircraft.Lambda[0]);
    401:   VecDestroy(&aircraft.Mup[0]);
    402:   VecDestroy(&P);
    403:   if (aircraft.eh) {
    404:     VecDestroy(&aircraft.Lambda2[0]);
    405:     VecDestroy(&aircraft.Mup2[0]);
    406:     VecDestroy(&aircraft.Dir);
    407:     VecDestroy(&aircraft.rhshp1[0]);
    408:     VecDestroy(&aircraft.rhshp2[0]);
    409:     VecDestroy(&aircraft.rhshp3[0]);
    410:     VecDestroy(&aircraft.rhshp4[0]);
    411:     VecDestroy(&aircraft.inthp1[0]);
    412:     VecDestroy(&aircraft.inthp2[0]);
    413:     VecDestroy(&aircraft.inthp3[0]);
    414:     VecDestroy(&aircraft.inthp4[0]);
    415:     MatDestroy(&aircraft.H);
    416:   }
    417:   PetscFinalize();
    418:   return 0;
    419: }

    421: /*
    422:    FormObjFunctionGradient - Evaluates the function and corresponding gradient.

    424:    Input Parameters:
    425:    tao - the Tao context
    426:    P   - the input vector
    427:    ctx - optional aircraft-defined context, as set by TaoSetObjectiveAndGradient()

    429:    Output Parameters:
    430:    f   - the newly evaluated function
    431:    G   - the newly evaluated gradient
    432: */
    433: PetscErrorCode FormObjFunctionGradient(Tao tao,Vec P,PetscReal *f,Vec G,void *ctx)
    434: {
    435:   Aircraft          actx = (Aircraft)ctx;
    436:   TS                ts = actx->ts;
    437:   Vec               Q;
    438:   const PetscScalar *p,*q;
    439:   PetscScalar       *u,*v,*w;
    440:   PetscInt          i;

    443:   VecGetArrayRead(P,&p);
    444:   VecGetArray(actx->V,&v);
    445:   VecGetArray(actx->W,&w);
    446:   for (i=0; i<actx->nsteps; i++) {
    447:     v[i] = p[2*i];
    448:     w[i] = p[2*i+1];
    449:   }
    450:   VecRestoreArrayRead(P,&p);
    451:   VecRestoreArray(actx->V,&v);
    452:   VecRestoreArray(actx->W,&w);

    454:   TSSetTime(ts,0.0);
    455:   TSSetStepNumber(ts,0);
    456:   TSSetFromOptions(ts);
    457:   TSSetTimeStep(ts,actx->ftime/actx->nsteps);

    459:   /* reinitialize system state */
    460:   VecGetArray(actx->U,&u);
    461:   u[0] = 2.0;
    462:   u[1] = 0;
    463:   VecRestoreArray(actx->U,&u);

    465:   /* reinitialize the integral value */
    466:   TSGetCostIntegral(ts,&Q);
    467:   VecSet(Q,0.0);

    469:   TSSolve(ts,actx->U);

    471:   /* Reset initial conditions for the adjoint integration */
    472:   VecSet(actx->Lambda[0],0.0);
    473:   VecSet(actx->Mup[0],0.0);
    474:   TSSetCostGradients(ts,1,actx->Lambda,actx->Mup);

    476:   TSAdjointSolve(ts);
    477:   VecCopy(actx->Mup[0],G);
    478:   TSGetCostIntegral(ts,&Q);
    479:   VecGetArrayRead(Q,&q);
    480:   *f   = q[0];
    481:   VecRestoreArrayRead(Q,&q);
    482:   return 0;
    483: }

    485: PetscErrorCode FormObjHessian(Tao tao,Vec P,Mat H,Mat Hpre,void *ctx)
    486: {
    487:   Aircraft          actx = (Aircraft)ctx;
    488:   const PetscScalar *p;
    489:   PetscScalar       *harr,*v,*w,one = 1.0;
    490:   PetscInt          ind[1];
    491:   PetscInt          *cols,i;
    492:   Vec               Dir;

    495:   /* set up control parameters */
    496:   VecGetArrayRead(P,&p);
    497:   VecGetArray(actx->V,&v);
    498:   VecGetArray(actx->W,&w);
    499:   for (i=0; i<actx->nsteps; i++) {
    500:     v[i] = p[2*i];
    501:     w[i] = p[2*i+1];
    502:   }
    503:   VecRestoreArrayRead(P,&p);
    504:   VecRestoreArray(actx->V,&v);
    505:   VecRestoreArray(actx->W,&w);

    507:   PetscMalloc1(2*actx->nsteps,&harr);
    508:   PetscMalloc1(2*actx->nsteps,&cols);
    509:   for (i=0; i<2*actx->nsteps; i++) cols[i] = i;
    510:   VecDuplicate(P,&Dir);
    511:   for (i=0; i<2*actx->nsteps; i++) {
    512:     ind[0] = i;
    513:     VecSet(Dir,0.0);
    514:     VecSetValues(Dir,1,ind,&one,INSERT_VALUES);
    515:     VecAssemblyBegin(Dir);
    516:     VecAssemblyEnd(Dir);
    517:     ComputeObjHessianWithSOA(Dir,harr,actx);
    518:     MatSetValues(H,1,ind,2*actx->nsteps,cols,harr,INSERT_VALUES);
    519:     MatAssemblyBegin(H,MAT_FINAL_ASSEMBLY);
    520:     MatAssemblyEnd(H,MAT_FINAL_ASSEMBLY);
    521:     if (H != Hpre) {
    522:       MatAssemblyBegin(Hpre,MAT_FINAL_ASSEMBLY);
    523:       MatAssemblyEnd(Hpre,MAT_FINAL_ASSEMBLY);
    524:     }
    525:   }
    526:   PetscFree(cols);
    527:   PetscFree(harr);
    528:   VecDestroy(&Dir);
    529:   return 0;
    530: }

    532: PetscErrorCode MatrixFreeObjHessian(Tao tao, Vec P, Mat H, Mat Hpre, void *ctx)
    533: {
    534:   Aircraft          actx = (Aircraft)ctx;
    535:   PetscScalar       *v,*w;
    536:   const PetscScalar *p;
    537:   PetscInt          i;

    539:   VecGetArrayRead(P,&p);
    540:   VecGetArray(actx->V,&v);
    541:   VecGetArray(actx->W,&w);
    542:   for (i=0; i<actx->nsteps; i++) {
    543:     v[i] = p[2*i];
    544:     w[i] = p[2*i+1];
    545:   }
    546:   VecRestoreArrayRead(P,&p);
    547:   VecRestoreArray(actx->V,&v);
    548:   VecRestoreArray(actx->W,&w);
    549:   return 0;
    550: }

    552: PetscErrorCode MyMatMult(Mat H_shell, Vec X, Vec Y)
    553: {
    554:   PetscScalar    *y;
    555:   void           *ptr;

    557:   MatShellGetContext(H_shell,&ptr);
    558:   VecGetArray(Y,&y);
    559:   ComputeObjHessianWithSOA(X,y,(Aircraft)ptr);
    560:   VecRestoreArray(Y,&y);
    561:   return 0;
    562: }

    564: PetscErrorCode ComputeObjHessianWithSOA(Vec Dir,PetscScalar arr[],Aircraft actx)
    565: {
    566:   TS                ts = actx->ts;
    567:   const PetscScalar *z_ptr;
    568:   PetscScalar       *u;
    569:   Vec               Q;
    570:   PetscInt          i;

    573:   /* Reset TSAdjoint so that AdjointSetUp will be called again */
    574:   TSAdjointReset(ts);

    576:   TSSetTime(ts,0.0);
    577:   TSSetStepNumber(ts,0);
    578:   TSSetFromOptions(ts);
    579:   TSSetTimeStep(ts,actx->ftime/actx->nsteps);
    580:   TSSetCostHessianProducts(actx->ts,1,actx->Lambda2,actx->Mup2,Dir);

    582:   /* reinitialize system state */
    583:   VecGetArray(actx->U,&u);
    584:   u[0] = 2.0;
    585:   u[1] = 0;
    586:   VecRestoreArray(actx->U,&u);

    588:   /* reinitialize the integral value */
    589:   TSGetCostIntegral(ts,&Q);
    590:   VecSet(Q,0.0);

    592:   /* initialize tlm variable */
    593:   MatZeroEntries(actx->Jacp);
    594:   MatAssemblyBegin(actx->Jacp,MAT_FINAL_ASSEMBLY);
    595:   MatAssemblyEnd(actx->Jacp,MAT_FINAL_ASSEMBLY);
    596:   TSAdjointSetForward(ts,actx->Jacp);

    598:   TSSolve(ts,actx->U);

    600:   /* Set terminal conditions for first- and second-order adjonts */
    601:   VecSet(actx->Lambda[0],0.0);
    602:   VecSet(actx->Mup[0],0.0);
    603:   VecSet(actx->Lambda2[0],0.0);
    604:   VecSet(actx->Mup2[0],0.0);
    605:   TSSetCostGradients(ts,1,actx->Lambda,actx->Mup);

    607:   TSGetCostIntegral(ts,&Q);

    609:   /* Reset initial conditions for the adjoint integration */
    610:   TSAdjointSolve(ts);

    612:   /* initial condition does not depend on p, so that lambda is not needed to assemble G */
    613:   VecGetArrayRead(actx->Mup2[0],&z_ptr);
    614:   for (i=0; i<2*actx->nsteps; i++) arr[i] = z_ptr[i];
    615:   VecRestoreArrayRead(actx->Mup2[0],&z_ptr);

    617:   /* Disable second-order adjoint mode */
    618:   TSAdjointReset(ts);
    619:   TSAdjointResetForward(ts);
    620:   return 0;
    621: }

    623: /*TEST
    624:     build:
    625:       requires: !complex !single

    627:     test:
    628:       args:  -ts_adapt_type none -ts_type rk -ts_rk_type 3 -viewer_binary_skip_info -tao_monitor -tao_gatol 1e-7

    630:     test:
    631:       suffix: 2
    632:       args:  -ts_adapt_type none -ts_type rk -ts_rk_type 3 -viewer_binary_skip_info -tao_monitor -tao_view -tao_type bntr -tao_bnk_pc_type none -exacthessian

    634:     test:
    635:       suffix: 3
    636:       args:  -ts_adapt_type none -ts_type rk -ts_rk_type 3 -viewer_binary_skip_info -tao_monitor -tao_view -tao_type bntr -tao_bnk_pc_type none -exacthessian -matrixfree
    637: TEST*/