Beispiel #1
0
Datei: ms.c Projekt: Kun-Qu/petsc
static PetscErrorCode SNESSolve_MS(SNES snes)
{
  SNES_MS        *ms = (SNES_MS*)snes->data;
  Vec            X = snes->vec_sol,F = snes->vec_func;
  PetscReal      fnorm;
  MatStructure   mstruct;
  PetscInt       i;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  snes->reason = SNES_CONVERGED_ITERATING;
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  if (!snes->vec_func_init_set) {
    ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
  } else {
    snes->vec_func_init_set = PETSC_FALSE;
  }
  if (snes->jacobian) {         /* This method does not require a Jacobian, but it is usually preconditioned by PBJacobi */
    ierr = SNESComputeJacobian(snes,snes->vec_sol,&snes->jacobian,&snes->jacobian_pre,&mstruct);CHKERRQ(ierr);
    ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,mstruct);CHKERRQ(ierr);
  }
  if (ms->norms) {
    if (!snes->norm_init_set) {
      ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
      if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
    } else {
      fnorm = snes->norm_init;
      snes->norm_init_set = PETSC_FALSE;
    }
    /* Monitor convergence */
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
    snes->iter = 0;
    snes->norm = fnorm;
    ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
    SNESLogConvHistory(snes,snes->norm,0);
    ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);

    /* set parameter for default relative tolerance convergence test */
    snes->ttol = fnorm*snes->rtol;
    /* Test for convergence */
    ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
    if (snes->reason) PetscFunctionReturn(0);
  }

  /* Call general purpose update function */
  if (snes->ops->update) {
    ierr = (*snes->ops->update)(snes,snes->iter);CHKERRQ(ierr);
  }
  for (i = 0; i < snes->max_its; i++) {
    ierr = SNESMSStep_3Sstar(snes,X,F);CHKERRQ(ierr);

    if (i+1 < snes->max_its || ms->norms) {
      ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
      if (snes->domainerror) {
        snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
        PetscFunctionReturn(0);
      }
    }

    if (ms->norms) {
      ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
      if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
      /* Monitor convergence */
      ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
      snes->iter = i+1;
      snes->norm = fnorm;
      ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
      SNESLogConvHistory(snes,snes->norm,0);
      ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);

      /* Test for convergence */
      ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
      if (snes->reason) PetscFunctionReturn(0);
    }

    /* Call general purpose update function */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }
  }
  if (!snes->reason) snes->reason = SNES_CONVERGED_ITS;
  PetscFunctionReturn(0);
}
Beispiel #2
0
EXTERN_C_END

/*
  SNESSolve_NCG - Solves a nonlinear system with the Nonlinear Conjugate Gradient method.

  Input Parameters:
. snes - the SNES context

  Output Parameter:
. outits - number of iterations until termination

  Application Interface Routine: SNESSolve()
*/
#undef __FUNCT__
#define __FUNCT__ "SNESSolve_NCG"
PetscErrorCode SNESSolve_NCG(SNES snes)
{
    SNES_NCG            *ncg = (SNES_NCG *)snes->data;
    Vec                 X, dX, lX, F, B, Fold;
    PetscReal           fnorm, ynorm, xnorm, beta = 0.0;
    PetscScalar         dXdotF, dXolddotFold, dXdotFold, lXdotF, lXdotFold;
    PetscInt            maxits, i;
    PetscErrorCode      ierr;
    SNESConvergedReason reason;
    PetscBool           lsSuccess = PETSC_TRUE;
    SNESLineSearch     linesearch;

    PetscFunctionBegin;
    snes->reason = SNES_CONVERGED_ITERATING;

    maxits = snes->max_its;            /* maximum number of iterations */
    X      = snes->vec_sol;            /* X^n */
    Fold   = snes->work[0];            /* The previous iterate of X */
    dX     = snes->work[1];            /* the preconditioned direction */
    lX     = snes->vec_sol_update;     /* the conjugate direction */
    F      = snes->vec_func;           /* residual vector */
    B      = snes->vec_rhs;            /* the right hand side */

    ierr = SNESGetSNESLineSearch(snes, &linesearch);
    CHKERRQ(ierr);

    ierr = PetscObjectTakeAccess(snes);
    CHKERRQ(ierr);
    snes->iter = 0;
    snes->norm = 0.;
    ierr = PetscObjectGrantAccess(snes);
    CHKERRQ(ierr);

    /* compute the initial function and preconditioned update dX */
    if (!snes->vec_func_init_set) {
        ierr = SNESComputeFunction(snes,X,F);
        CHKERRQ(ierr);
        if (snes->domainerror) {
            snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
            PetscFunctionReturn(0);
        }
    } else {
        snes->vec_func_init_set = PETSC_FALSE;
    }
    if (!snes->norm_init_set) {
        /* convergence test */
        ierr = VecNorm(F, NORM_2, &fnorm);
        CHKERRQ(ierr); /* fnorm <- ||F||  */
        if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
    } else {
        fnorm = snes->norm_init;
        snes->norm_init_set = PETSC_FALSE;
    }
    ierr = PetscObjectTakeAccess(snes);
    CHKERRQ(ierr);
    snes->norm = fnorm;
    ierr = PetscObjectGrantAccess(snes);
    CHKERRQ(ierr);
    SNESLogConvHistory(snes,fnorm,0);
    ierr = SNESMonitor(snes,0,fnorm);
    CHKERRQ(ierr);

    /* set parameter for default relative tolerance convergence test */
    snes->ttol = fnorm*snes->rtol;
    /* test convergence */
    ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);
    CHKERRQ(ierr);
    if (snes->reason) PetscFunctionReturn(0);

    /* Call general purpose update function */
    if (snes->ops->update) {
        ierr = (*snes->ops->update)(snes, snes->iter);
        CHKERRQ(ierr);
    }

    /* first update -- just use the (preconditioned) residual direction for the initial conjugate direction */

    if (snes->pc && snes->pcside == PC_RIGHT) {
        ierr = VecCopy(X, dX);
        CHKERRQ(ierr);
        ierr = SNESSetInitialFunction(snes->pc, F);
        CHKERRQ(ierr);
        ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);
        CHKERRQ(ierr);
        ierr = SNESSolve(snes->pc, B, dX);
        CHKERRQ(ierr);
        ierr = SNESGetConvergedReason(snes->pc,&reason);
        CHKERRQ(ierr);
        if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) {
            snes->reason = SNES_DIVERGED_INNER;
            PetscFunctionReturn(0);
        }
        ierr = VecAYPX(dX,-1.0,X);
        CHKERRQ(ierr);
    } else {
        ierr = VecCopy(F, dX);
        CHKERRQ(ierr);
    }
    ierr = VecCopy(dX, lX);
    CHKERRQ(ierr);
    ierr = VecDot(F, dX, &dXdotF);
    CHKERRQ(ierr);
    /*
    } else {
      ierr = SNESNCGComputeYtJtF_Private(snes, X, F, dX, W, G, &dXdotF);CHKERRQ(ierr);
    }
     */
    for (i = 1; i < maxits + 1; i++) {
        lsSuccess = PETSC_TRUE;
        /* some update types require the old update direction or conjugate direction */
        if (ncg->type != SNES_NCG_FR) {
            ierr = VecCopy(F, Fold);
            CHKERRQ(ierr);
        }
        ierr = SNESLineSearchApply(linesearch, X, F, &fnorm, lX);
        CHKERRQ(ierr);
        ierr = SNESLineSearchGetSuccess(linesearch, &lsSuccess);
        CHKERRQ(ierr);
        if (!lsSuccess) {
            if (++snes->numFailures >= snes->maxFailures) {
                snes->reason = SNES_DIVERGED_LINE_SEARCH;
                PetscFunctionReturn(0);
            }
        }
        if (snes->nfuncs >= snes->max_funcs) {
            snes->reason = SNES_DIVERGED_FUNCTION_COUNT;
            PetscFunctionReturn(0);
        }
        if (snes->domainerror) {
            snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
            PetscFunctionReturn(0);
        }
        ierr = SNESLineSearchGetNorms(linesearch, &xnorm, &fnorm, &ynorm);
        CHKERRQ(ierr);
        /* Monitor convergence */
        ierr = PetscObjectTakeAccess(snes);
        CHKERRQ(ierr);
        snes->iter = i;
        snes->norm = fnorm;
        ierr = PetscObjectGrantAccess(snes);
        CHKERRQ(ierr);
        SNESLogConvHistory(snes,snes->norm,0);
        ierr = SNESMonitor(snes,snes->iter,snes->norm);
        CHKERRQ(ierr);

        /* Test for convergence */
        ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);
        CHKERRQ(ierr);
        if (snes->reason) PetscFunctionReturn(0);

        /* Call general purpose update function */
        if (snes->ops->update) {
            ierr = (*snes->ops->update)(snes, snes->iter);
            CHKERRQ(ierr);
        }
        if (snes->pc && snes->pcside == PC_RIGHT) {
            ierr = VecCopy(X,dX);
            CHKERRQ(ierr);
            ierr = SNESSetInitialFunction(snes->pc, F);
            CHKERRQ(ierr);
            ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);
            CHKERRQ(ierr);
            ierr = SNESSolve(snes->pc, B, dX);
            CHKERRQ(ierr);
            ierr = SNESGetConvergedReason(snes->pc,&reason);
            CHKERRQ(ierr);
            if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) {
                snes->reason = SNES_DIVERGED_INNER;
                PetscFunctionReturn(0);
            }
            ierr = VecAYPX(dX,-1.0,X);
            CHKERRQ(ierr);
        } else {
            ierr = VecCopy(F, dX);
            CHKERRQ(ierr);
        }

        /* compute the conjugate direction lX = dX + beta*lX with beta = ((dX, dX) / (dX_old, dX_old) (Fletcher-Reeves update)*/
        switch(ncg->type) {
        case SNES_NCG_FR: /* Fletcher-Reeves */
            dXolddotFold = dXdotF;
            ierr = VecDot(dX, dX, &dXdotF);
            CHKERRQ(ierr);
            beta = PetscRealPart(dXdotF / dXolddotFold);
            break;
        case SNES_NCG_PRP: /* Polak-Ribiere-Poylak */
            dXolddotFold = dXdotF;
            ierr = VecDotBegin(F, dX, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotBegin(Fold, dX, &dXdotFold);
            CHKERRQ(ierr);
            ierr = VecDotEnd(F, dX, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotEnd(Fold, dX, &dXdotFold);
            CHKERRQ(ierr);
            beta = PetscRealPart(((dXdotF - dXdotFold) / dXolddotFold));
            if (beta < 0.0) beta = 0.0; /* restart */
            break;
        case SNES_NCG_HS: /* Hestenes-Stiefel */
            ierr = VecDotBegin(dX, F, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotBegin(dX, Fold, &dXdotFold);
            CHKERRQ(ierr);
            ierr = VecDotBegin(lX, F, &lXdotF);
            CHKERRQ(ierr);
            ierr = VecDotBegin(lX, Fold, &lXdotFold);
            CHKERRQ(ierr);
            ierr = VecDotEnd(dX, F, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotEnd(dX, Fold, &dXdotFold);
            CHKERRQ(ierr);
            ierr = VecDotEnd(lX, F, &lXdotF);
            CHKERRQ(ierr);
            ierr = VecDotEnd(lX, Fold, &lXdotFold);
            CHKERRQ(ierr);
            beta = PetscRealPart((dXdotF - dXdotFold) / (lXdotF - lXdotFold));
            break;
        case SNES_NCG_DY: /* Dai-Yuan */
            ierr = VecDotBegin(dX, F, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotBegin(lX, F, &lXdotF);
            CHKERRQ(ierr);
            ierr = VecDotBegin(lX, Fold, &lXdotFold);
            CHKERRQ(ierr);
            ierr = VecDotEnd(dX, F, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotEnd(lX, F, &lXdotF);
            CHKERRQ(ierr);
            ierr = VecDotEnd(lX, Fold, &lXdotFold);
            CHKERRQ(ierr);
            beta = PetscRealPart(dXdotF / (lXdotFold - lXdotF));
            CHKERRQ(ierr);
            break;
        case SNES_NCG_CD: /* Conjugate Descent */
            ierr = VecDotBegin(dX, F, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotBegin(lX, Fold, &lXdotFold);
            CHKERRQ(ierr);
            ierr = VecDotEnd(dX, F, &dXdotF);
            CHKERRQ(ierr);
            ierr = VecDotEnd(lX, Fold, &lXdotFold);
            CHKERRQ(ierr);
            beta = PetscRealPart(dXdotF / lXdotFold);
            CHKERRQ(ierr);
            break;
        }
        if (ncg->monitor) {
            ierr = PetscViewerASCIIPrintf(ncg->monitor, "beta = %e\n", beta);
            CHKERRQ(ierr);
        }
        ierr = VecAYPX(lX, beta, dX);
        CHKERRQ(ierr);
    }
    ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);
    CHKERRQ(ierr);
    if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
    PetscFunctionReturn(0);
}
Beispiel #3
0
PetscErrorCode SNESSolve_NEWTONLS(SNES snes)
{
  PetscErrorCode      ierr;
  PetscInt            maxits,i,lits;
  PetscBool           lssucceed;
  MatStructure        flg = DIFFERENT_NONZERO_PATTERN;
  PetscReal           fnorm,gnorm,xnorm,ynorm;
  Vec                 Y,X,F,G,W,FPC;
  KSPConvergedReason  kspreason;
  PetscBool           domainerror;
  SNESLineSearch      linesearch;
  SNESConvergedReason reason;

  PetscFunctionBegin;
  snes->numFailures            = 0;
  snes->numLinearSolveFailures = 0;
  snes->reason                 = SNES_CONVERGED_ITERATING;

  maxits        = snes->max_its;        /* maximum number of iterations */
  X             = snes->vec_sol;        /* solution vector */
  F             = snes->vec_func;       /* residual vector */
  Y             = snes->vec_sol_update; /* newton step */
  G             = snes->work[0];
  W             = snes->work[1];

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.0;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  ierr = SNESGetSNESLineSearch(snes, &linesearch);CHKERRQ(ierr);
  if (!snes->vec_func_init_set) {
    ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
    ierr = SNESGetFunctionDomainError(snes, &domainerror);CHKERRQ(ierr);
    if (domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
  } else {
    snes->vec_func_init_set = PETSC_FALSE;
  }
  if (!snes->norm_init_set) {
    ierr = VecNormBegin(F,NORM_2,&fnorm);CHKERRQ(ierr);        /* fnorm <- ||F||  */
    ierr = VecNormEnd(F,NORM_2,&fnorm);CHKERRQ(ierr);
    if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number");
  } else {
    fnorm = snes->norm_init;
    snes->norm_init_set = PETSC_FALSE;
  }
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  SNESLogConvHistory(snes,fnorm,0);
  ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);

  /* set parameter for default relative tolerance convergence test */
  snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);

  for (i=0; i<maxits; i++) {

    /* Call general purpose update function */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }

    /* apply the nonlinear preconditioner if it's right preconditioned */
    if (snes->pc && snes->pcside == PC_RIGHT) {
      ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr);
      ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr);
      ierr = SNESSolve(snes->pc, snes->vec_rhs, X);CHKERRQ(ierr);
      ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr);
      if (reason < 0  && reason != SNES_DIVERGED_MAX_IT) {
        snes->reason = SNES_DIVERGED_INNER;
        PetscFunctionReturn(0);
      }
      ierr = SNESGetFunction(snes->pc, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr);
      ierr = VecCopy(FPC, F);CHKERRQ(ierr);
      ierr = SNESGetFunctionNorm(snes->pc, &fnorm);CHKERRQ(ierr);
    }

    /* Solve J Y = F, where J is Jacobian matrix */
    ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);
    ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr);
    ierr = SNES_KSPSolve(snes,snes->ksp,F,Y);CHKERRQ(ierr);
    ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr);
    if (kspreason < 0) {
      if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
        ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr);
        snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
        break;
      }
    }
    ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr);
    snes->linear_its += lits;
    ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr);

    if (PetscLogPrintInfo){
      ierr = SNESNEWTONLSCheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr);
    }

    /* Compute a (scaled) negative update in the line search routine:
         X <- X - lambda*Y
       and evaluate F = function(X) (depends on the line search).
    */
    gnorm = fnorm;
    ierr = SNESLineSearchApply(linesearch, X, F, &fnorm, Y);CHKERRQ(ierr);
    ierr = SNESLineSearchGetSuccess(linesearch, &lssucceed);CHKERRQ(ierr);
    ierr = SNESLineSearchGetNorms(linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr);
    ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)gnorm,(double)fnorm,(double)ynorm,(int)lssucceed);CHKERRQ(ierr);
    if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
    ierr = SNESGetFunctionDomainError(snes, &domainerror);CHKERRQ(ierr);
    if (domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
    if (!lssucceed) {
      if (snes->stol*xnorm > ynorm) {
        snes->reason = SNES_CONVERGED_SNORM_RELATIVE;
        PetscFunctionReturn(0);
      }
      if (++snes->numFailures >= snes->maxFailures) {
        PetscBool  ismin;
        snes->reason = SNES_DIVERGED_LINE_SEARCH;
        ierr = SNESNEWTONLSCheckLocalMin_Private(snes,snes->jacobian,F,W,fnorm,&ismin);CHKERRQ(ierr);
        if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN;
        break;
      }
    }
    /* Monitor convergence */
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
    snes->iter = i+1;
    snes->norm = fnorm;
    ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
    SNESLogConvHistory(snes,snes->norm,lits);
    ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
    /* Test for convergence */
    ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
    if (snes->reason) break;
  }
  if (i == maxits) {
    ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr);
    if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
  }
  PetscFunctionReturn(0);
}
Beispiel #4
0
PetscErrorCode SNESSolve_VINEWTONRSLS(SNES snes)
{
  SNES_VINEWTONRSLS  *vi = (SNES_VINEWTONRSLS*)snes->data;
  PetscErrorCode     ierr;
  PetscInt           maxits,i,lits;
  PetscBool          lssucceed;
  MatStructure       flg = DIFFERENT_NONZERO_PATTERN;
  PetscReal          fnorm,gnorm,xnorm=0,ynorm;
  Vec                Y,X,F;
  KSPConvergedReason kspreason;

  PetscFunctionBegin;

  snes->numFailures            = 0;
  snes->numLinearSolveFailures = 0;
  snes->reason                 = SNES_CONVERGED_ITERATING;

  maxits        = snes->max_its;        /* maximum number of iterations */
  X             = snes->vec_sol;        /* solution vector */
  F             = snes->vec_func;       /* residual vector */
  Y             = snes->work[0];        /* work vectors */

  ierr = SNESLineSearchSetVIFunctions(snes->linesearch, SNESVIProjectOntoBounds, SNESVIComputeInactiveSetFnorm);CHKERRQ(ierr);
  ierr = SNESLineSearchSetVecs(snes->linesearch, X, PETSC_NULL, PETSC_NULL, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr);
  ierr = SNESLineSearchSetUp(snes->linesearch);CHKERRQ(ierr);

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.0;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);

  ierr = SNESVIProjectOntoBounds(snes,X);CHKERRQ(ierr);
  ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
  if (snes->domainerror) {
    snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
    PetscFunctionReturn(0);
  }
  ierr = SNESVIComputeInactiveSetFnorm(snes,F,X,&fnorm);CHKERRQ(ierr);
  ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr);        /* xnorm <- ||x||  */
  ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr);
  if (PetscIsInfOrNanReal(fnorm)) SETERRQ(((PetscObject)X)->comm,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number");

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  SNESLogConvHistory(snes,fnorm,0);
  ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);

  /* set parameter for default relative tolerance convergence test */
  snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);


  for (i=0; i<maxits; i++) {

    IS         IS_act,IS_inact; /* _act -> active set _inact -> inactive set */
    IS         IS_redact; /* redundant active set */
    VecScatter scat_act,scat_inact;
    PetscInt   nis_act,nis_inact;
    Vec        Y_act,Y_inact,F_inact;
    Mat        jac_inact_inact,prejac_inact_inact;
    PetscBool  isequal;

    /* Call general purpose update function */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }
    ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);


        /* Create active and inactive index sets */

    /*original
    ierr = SNESVICreateIndexSets_RS(snes,X,F,&IS_act,&IS_inact);CHKERRQ(ierr);
     */
    ierr = SNESVIGetActiveSetIS(snes,X,F,&IS_act);CHKERRQ(ierr);

    if (vi->checkredundancy) {
      (*vi->checkredundancy)(snes,IS_act,&IS_redact,vi->ctxP);CHKERRQ(ierr);
      if (IS_redact){
        ierr = ISSort(IS_redact);CHKERRQ(ierr);
        ierr = ISComplement(IS_redact,X->map->rstart,X->map->rend,&IS_inact);CHKERRQ(ierr);
        ierr = ISDestroy(&IS_redact);CHKERRQ(ierr);
      }
      else {
        ierr = ISComplement(IS_act,X->map->rstart,X->map->rend,&IS_inact);CHKERRQ(ierr);
      }
    } else {
      ierr = ISComplement(IS_act,X->map->rstart,X->map->rend,&IS_inact);CHKERRQ(ierr);
    }


    /* Create inactive set submatrix */
    ierr = MatGetSubMatrix(snes->jacobian,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);CHKERRQ(ierr);

    if (0) {                    /* Dead code (temporary developer hack) */
      IS keptrows;
      ierr = MatFindNonzeroRows(jac_inact_inact,&keptrows);CHKERRQ(ierr);
      if (keptrows) {
        PetscInt       cnt,*nrows,k;
        const PetscInt *krows,*inact;
        PetscInt       rstart=jac_inact_inact->rmap->rstart;

        ierr = MatDestroy(&jac_inact_inact);CHKERRQ(ierr);
        ierr = ISDestroy(&IS_act);CHKERRQ(ierr);

        ierr = ISGetLocalSize(keptrows,&cnt);CHKERRQ(ierr);
        ierr = ISGetIndices(keptrows,&krows);CHKERRQ(ierr);
        ierr = ISGetIndices(IS_inact,&inact);CHKERRQ(ierr);
        ierr = PetscMalloc(cnt*sizeof(PetscInt),&nrows);CHKERRQ(ierr);
        for (k=0; k<cnt; k++) {
          nrows[k] = inact[krows[k]-rstart];
        }
        ierr = ISRestoreIndices(keptrows,&krows);CHKERRQ(ierr);
        ierr = ISRestoreIndices(IS_inact,&inact);CHKERRQ(ierr);
        ierr = ISDestroy(&keptrows);CHKERRQ(ierr);
        ierr = ISDestroy(&IS_inact);CHKERRQ(ierr);

        ierr = ISCreateGeneral(((PetscObject)snes)->comm,cnt,nrows,PETSC_OWN_POINTER,&IS_inact);CHKERRQ(ierr);
        ierr = ISComplement(IS_inact,F->map->rstart,F->map->rend,&IS_act);CHKERRQ(ierr);
        ierr = MatGetSubMatrix(snes->jacobian,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&jac_inact_inact);CHKERRQ(ierr);
      }
    }
    ierr = DMSetVI(snes->dm,IS_inact);CHKERRQ(ierr);
    /* remove later */

    /*
  ierr = VecView(vi->xu,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xu))->comm));CHKERRQ(ierr);
  ierr = VecView(vi->xl,PETSC_VIEWER_BINARY_(((PetscObject)(vi->xl))->comm));CHKERRQ(ierr);
  ierr = VecView(X,PETSC_VIEWER_BINARY_(((PetscObject)X)->comm));CHKERRQ(ierr);
  ierr = VecView(F,PETSC_VIEWER_BINARY_(((PetscObject)F)->comm));CHKERRQ(ierr);
  ierr = ISView(IS_inact,PETSC_VIEWER_BINARY_(((PetscObject)IS_inact)->comm));CHKERRQ(ierr);
     */

    /* Get sizes of active and inactive sets */
    ierr = ISGetLocalSize(IS_act,&nis_act);CHKERRQ(ierr);
    ierr = ISGetLocalSize(IS_inact,&nis_inact);CHKERRQ(ierr);

    /* Create active and inactive set vectors */
    ierr = SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&F_inact);CHKERRQ(ierr);
    ierr = SNESCreateSubVectors_VINEWTONRSLS(snes,nis_act,&Y_act);CHKERRQ(ierr);
    ierr = SNESCreateSubVectors_VINEWTONRSLS(snes,nis_inact,&Y_inact);CHKERRQ(ierr);

    /* Create scatter contexts */
    ierr = VecScatterCreate(Y,IS_act,Y_act,PETSC_NULL,&scat_act);CHKERRQ(ierr);
    ierr = VecScatterCreate(Y,IS_inact,Y_inact,PETSC_NULL,&scat_inact);CHKERRQ(ierr);

    /* Do a vec scatter to active and inactive set vectors */
    ierr = VecScatterBegin(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
    ierr = VecScatterEnd(scat_inact,F,F_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);

    ierr = VecScatterBegin(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
    ierr = VecScatterEnd(scat_act,Y,Y_act,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);

    ierr = VecScatterBegin(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
    ierr = VecScatterEnd(scat_inact,Y,Y_inact,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);

    /* Active set direction = 0 */
    ierr = VecSet(Y_act,0);CHKERRQ(ierr);
    if (snes->jacobian != snes->jacobian_pre) {
      ierr = MatGetSubMatrix(snes->jacobian_pre,IS_inact,IS_inact,MAT_INITIAL_MATRIX,&prejac_inact_inact);CHKERRQ(ierr);
    } else prejac_inact_inact = jac_inact_inact;

    ierr = ISEqual(vi->IS_inact_prev,IS_inact,&isequal);CHKERRQ(ierr);
    if (!isequal) {
      ierr = SNESVIResetPCandKSP(snes,jac_inact_inact,prejac_inact_inact);CHKERRQ(ierr);
      flg  = DIFFERENT_NONZERO_PATTERN;
    }

    /*      ierr = ISView(IS_inact,0);CHKERRQ(ierr); */
    /*      ierr = ISView(IS_act,0);CHKERRQ(ierr);*/
    /*      ierr = MatView(snes->jacobian_pre,0); */



    ierr = KSPSetOperators(snes->ksp,jac_inact_inact,prejac_inact_inact,flg);CHKERRQ(ierr);
    ierr = KSPSetUp(snes->ksp);CHKERRQ(ierr);
    {
      PC        pc;
      PetscBool flg;
      ierr = KSPGetPC(snes->ksp,&pc);CHKERRQ(ierr);
      ierr = PetscObjectTypeCompare((PetscObject)pc,PCFIELDSPLIT,&flg);CHKERRQ(ierr);
      if (flg) {
        KSP      *subksps;
        ierr = PCFieldSplitGetSubKSP(pc,PETSC_NULL,&subksps);CHKERRQ(ierr);
        ierr = KSPGetPC(subksps[0],&pc);CHKERRQ(ierr);
        ierr = PetscFree(subksps);CHKERRQ(ierr);
        ierr = PetscObjectTypeCompare((PetscObject)pc,PCBJACOBI,&flg);CHKERRQ(ierr);
        if (flg) {
          PetscInt       n,N = 101*101,j,cnts[3] = {0,0,0};
          const PetscInt *ii;

          ierr = ISGetSize(IS_inact,&n);CHKERRQ(ierr);
          ierr = ISGetIndices(IS_inact,&ii);CHKERRQ(ierr);
          for (j=0; j<n; j++) {
            if (ii[j] < N) cnts[0]++;
            else if (ii[j] < 2*N) cnts[1]++;
            else if (ii[j] < 3*N) cnts[2]++;
          }
          ierr = ISRestoreIndices(IS_inact,&ii);CHKERRQ(ierr);

          ierr = PCBJacobiSetTotalBlocks(pc,3,cnts);CHKERRQ(ierr);
        }
      }
    }

    ierr = SNES_KSPSolve(snes,snes->ksp,F_inact,Y_inact);CHKERRQ(ierr);
    ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr);
    if (kspreason < 0) {
      if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
        ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr);
        snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
        break;
      }
     }

    ierr = VecScatterBegin(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
    ierr = VecScatterEnd(scat_act,Y_act,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
    ierr = VecScatterBegin(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
    ierr = VecScatterEnd(scat_inact,Y_inact,Y,INSERT_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);

    ierr = VecDestroy(&F_inact);CHKERRQ(ierr);
    ierr = VecDestroy(&Y_act);CHKERRQ(ierr);
    ierr = VecDestroy(&Y_inact);CHKERRQ(ierr);
    ierr = VecScatterDestroy(&scat_act);CHKERRQ(ierr);
    ierr = VecScatterDestroy(&scat_inact);CHKERRQ(ierr);
    ierr = ISDestroy(&IS_act);CHKERRQ(ierr);
    if (!isequal) {
      ierr = ISDestroy(&vi->IS_inact_prev);CHKERRQ(ierr);
      ierr = ISDuplicate(IS_inact,&vi->IS_inact_prev);CHKERRQ(ierr);
    }
    ierr = ISDestroy(&IS_inact);CHKERRQ(ierr);
    ierr = MatDestroy(&jac_inact_inact);CHKERRQ(ierr);
    if (snes->jacobian != snes->jacobian_pre) {
      ierr = MatDestroy(&prejac_inact_inact);CHKERRQ(ierr);
    }
    ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr);
    snes->linear_its += lits;
    ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr);
    /*
    if (snes->ops->precheck) {
      PetscBool changed_y = PETSC_FALSE;
      ierr = (*snes->ops->precheck)(snes,X,Y,snes->precheck,&changed_y);CHKERRQ(ierr);
    }

    if (PetscLogPrintInfo){
      ierr = SNESVICheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr);
    }
    */
    /* Compute a (scaled) negative update in the line search routine:
         Y <- X - lambda*Y
       and evaluate G = function(Y) (depends on the line search).
    */
    ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr);
    ynorm = 1; gnorm = fnorm;
    ierr = SNESLineSearchApply(snes->linesearch, X, F, &gnorm, Y);CHKERRQ(ierr);
    ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &gnorm, &ynorm);CHKERRQ(ierr);
    ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);CHKERRQ(ierr);
    if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      ierr = DMDestroyVI(snes->dm);CHKERRQ(ierr);
      PetscFunctionReturn(0);
    }
    ierr = SNESLineSearchGetSuccess(snes->linesearch, &lssucceed);CHKERRQ(ierr);

    if (!lssucceed) {
      if (++snes->numFailures >= snes->maxFailures) {
        PetscBool ismin;
        snes->reason = SNES_DIVERGED_LINE_SEARCH;
        ierr = SNESVICheckLocalMin_Private(snes,snes->jacobian,F,X,gnorm,&ismin);CHKERRQ(ierr);
        if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN;
        break;
      }
    }
    /* Update function and solution vectors */
    fnorm = gnorm;
    /* Monitor convergence */
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
    snes->iter = i+1;
    snes->norm = fnorm;
    ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
    SNESLogConvHistory(snes,snes->norm,lits);
    ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
    /* Test for convergence, xnorm = || X || */
    if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); }
    ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
    if (snes->reason) break;
  }
  ierr = DMDestroyVI(snes->dm);CHKERRQ(ierr);
  if (i == maxits) {
    ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr);
    if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
  }
  PetscFunctionReturn(0);
}
Beispiel #5
0
Datei: tr.c Projekt: Kun-Qu/petsc
static PetscErrorCode SNESSolve_TR(SNES snes)
{
  SNES_TR             *neP = (SNES_TR*)snes->data;
  Vec                 X,F,Y,G,Ytmp;
  PetscErrorCode      ierr;
  PetscInt            maxits,i,lits;
  MatStructure        flg = DIFFERENT_NONZERO_PATTERN;
  PetscReal           rho,fnorm,gnorm,gpnorm,xnorm=0,delta,nrm,ynorm,norm1;
  PetscScalar         cnorm;
  KSP                 ksp;
  SNESConvergedReason reason = SNES_CONVERGED_ITERATING;
  PetscBool           conv = PETSC_FALSE,breakout = PETSC_FALSE;
  PetscBool          domainerror;

  PetscFunctionBegin;
  maxits	= snes->max_its;	/* maximum number of iterations */
  X		= snes->vec_sol;	/* solution vector */
  F		= snes->vec_func;	/* residual vector */
  Y		= snes->work[0];	/* work vectors */
  G		= snes->work[1];
  Ytmp          = snes->work[2];

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);

  if (!snes->vec_func_init_set) {
    ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);          /* F(X) */
    ierr = SNESGetFunctionDomainError(snes, &domainerror);CHKERRQ(ierr);
    if (domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
  } else {
    snes->vec_func_init_set = PETSC_FALSE;
  }

  if (!snes->norm_init_set) {
    ierr = VecNorm(F,NORM_2,&fnorm);CHKERRQ(ierr);             /* fnorm <- || F || */
    if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"User provided compute function generated a Not-a-Number");
  } else {
    fnorm = snes->norm_init;
    snes->norm_init_set = PETSC_FALSE;
  }

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  delta = neP->delta0*fnorm;         
  neP->delta = delta;
  SNESLogConvHistory(snes,fnorm,0);
  ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);

  /* set parameter for default relative tolerance convergence test */
  snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);

  /* Set the stopping criteria to use the More' trick. */
  ierr = PetscOptionsGetBool(PETSC_NULL,"-snes_tr_ksp_regular_convergence_test",&conv,PETSC_NULL);CHKERRQ(ierr);
  if (!conv) {
    SNES_TR_KSPConverged_Ctx *ctx;
    ierr = SNESGetKSP(snes,&ksp);CHKERRQ(ierr);
    ierr = PetscNew(SNES_TR_KSPConverged_Ctx,&ctx);CHKERRQ(ierr);
    ctx->snes = snes;
    ierr = KSPDefaultConvergedCreate(&ctx->ctx);CHKERRQ(ierr);
    ierr = KSPSetConvergenceTest(ksp,SNES_TR_KSPConverged_Private,ctx,SNES_TR_KSPConverged_Destroy);CHKERRQ(ierr);
    ierr = PetscInfo(snes,"Using Krylov convergence test SNES_TR_KSPConverged_Private\n");CHKERRQ(ierr);
  }
 
  for (i=0; i<maxits; i++) {

    /* Call general purpose update function */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }

    /* Solve J Y = F, where J is Jacobian matrix */
    ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);
    ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr);
    ierr = SNES_KSPSolve(snes,snes->ksp,F,Ytmp);CHKERRQ(ierr);
    ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr);
    snes->linear_its += lits;
    ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr);
    ierr = VecNorm(Ytmp,NORM_2,&nrm);CHKERRQ(ierr);
    norm1 = nrm;
    while(1) {
      ierr = VecCopy(Ytmp,Y);CHKERRQ(ierr);
      nrm = norm1;

      /* Scale Y if need be and predict new value of F norm */
      if (nrm >= delta) {
        nrm = delta/nrm;
        gpnorm = (1.0 - nrm)*fnorm;
        cnorm = nrm;
        ierr = PetscInfo1(snes,"Scaling direction by %G\n",nrm);CHKERRQ(ierr);
        ierr = VecScale(Y,cnorm);CHKERRQ(ierr);
        nrm = gpnorm;
        ynorm = delta;
      } else {
        gpnorm = 0.0;
        ierr = PetscInfo(snes,"Direction is in Trust Region\n");CHKERRQ(ierr);
        ynorm = nrm;
      }
      ierr = VecAYPX(Y,-1.0,X);CHKERRQ(ierr);            /* Y <- X - Y */
      ierr = VecCopy(X,snes->vec_sol_update);CHKERRQ(ierr);
      ierr = SNESComputeFunction(snes,Y,G);CHKERRQ(ierr); /*  F(X) */
      ierr = VecNorm(G,NORM_2,&gnorm);CHKERRQ(ierr);      /* gnorm <- || g || */
      if (fnorm == gpnorm) rho = 0.0;
      else rho = (fnorm*fnorm - gnorm*gnorm)/(fnorm*fnorm - gpnorm*gpnorm); 

      /* Update size of trust region */
      if      (rho < neP->mu)  delta *= neP->delta1;
      else if (rho < neP->eta) delta *= neP->delta2;
      else                     delta *= neP->delta3;
      ierr = PetscInfo3(snes,"fnorm=%G, gnorm=%G, ynorm=%G\n",fnorm,gnorm,ynorm);CHKERRQ(ierr);
      ierr = PetscInfo3(snes,"gpred=%G, rho=%G, delta=%G\n",gpnorm,rho,delta);CHKERRQ(ierr);
      neP->delta = delta;
      if (rho > neP->sigma) break;
      ierr = PetscInfo(snes,"Trying again in smaller region\n");CHKERRQ(ierr);
      /* check to see if progress is hopeless */
      neP->itflag = PETSC_FALSE;
      ierr = SNES_TR_Converged_Private(snes,snes->iter,xnorm,ynorm,fnorm,&reason,snes->cnvP);CHKERRQ(ierr);
      if (!reason) { ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&reason,snes->cnvP);CHKERRQ(ierr); }
      if (reason) {
        /* We're not progressing, so return with the current iterate */
        ierr = SNESMonitor(snes,i+1,fnorm);CHKERRQ(ierr);
        breakout = PETSC_TRUE;
        break;
      }
      snes->numFailures++;
    }
    if (!breakout) {
      /* Update function and solution vectors */
      fnorm = gnorm;
      ierr = VecCopy(G,F);CHKERRQ(ierr);
      ierr = VecCopy(Y,X);CHKERRQ(ierr);
      /* Monitor convergence */
      ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
      snes->iter = i+1;
      snes->norm = fnorm;
      ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
      SNESLogConvHistory(snes,snes->norm,lits);
      ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
      /* Test for convergence, xnorm = || X || */
      neP->itflag = PETSC_TRUE;
      if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); }
      ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&reason,snes->cnvP);CHKERRQ(ierr);
      if (reason) break;
    } else {
      break;
    }
  }
  if (i == maxits) {
    ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr);
    if (!reason) reason = SNES_DIVERGED_MAX_IT;
  }
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->reason = reason;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Beispiel #6
0
PetscErrorCode SNESSolve_LS(SNES snes)
{ 
  SNES_LS            *neP = (SNES_LS*)snes->data;
  PetscErrorCode     ierr;
  PetscInt           maxits,i,lits;
  PetscTruth         lssucceed;
  MatStructure       flg = DIFFERENT_NONZERO_PATTERN;
  PetscReal          fnorm,gnorm,xnorm=0,ynorm;
  Vec                Y,X,F,G,W;
  KSPConvergedReason kspreason;

  PetscFunctionBegin;
  snes->numFailures            = 0;
  snes->numLinearSolveFailures = 0;
  snes->reason                 = SNES_CONVERGED_ITERATING;

  maxits	= snes->max_its;	/* maximum number of iterations */
  X		= snes->vec_sol;	/* solution vector */
  F		= snes->vec_func;	/* residual vector */
  Y		= snes->work[0];	/* work vectors */
  G		= snes->work[1];
  W		= snes->work[2];

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.0;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
  if (snes->domainerror) {
    snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
    PetscFunctionReturn(0);
  }
  ierr = VecNormBegin(F,NORM_2,&fnorm);CHKERRQ(ierr);	/* fnorm <- ||F||  */
  ierr = VecNormBegin(X,NORM_2,&xnorm);CHKERRQ(ierr);	/* xnorm <- ||x||  */
  ierr = VecNormEnd(F,NORM_2,&fnorm);CHKERRQ(ierr);
  ierr = VecNormEnd(X,NORM_2,&xnorm);CHKERRQ(ierr);
  if PetscIsInfOrNanReal(fnorm) SETERRQ(PETSC_ERR_FP,"User provided compute function generated a Not-a-Number");
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  SNESLogConvHistory(snes,fnorm,0);
  SNESMonitor(snes,0,fnorm);

  /* set parameter for default relative tolerance convergence test */
  snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);

  for (i=0; i<maxits; i++) {

    /* Call general purpose update function */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }

    /* Solve J Y = F, where J is Jacobian matrix */
    ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);
    ierr = KSPSetOperators(snes->ksp,snes->jacobian,snes->jacobian_pre,flg);CHKERRQ(ierr);
    ierr = SNES_KSPSolve(snes,snes->ksp,F,Y);CHKERRQ(ierr);
    ierr = KSPGetConvergedReason(snes->ksp,&kspreason);CHKERRQ(ierr);
    if (kspreason < 0) {
      if (++snes->numLinearSolveFailures >= snes->maxLinearSolveFailures) {
        ierr = PetscInfo2(snes,"iter=%D, number linear solve failures %D greater than current SNES allowed, stopping solve\n",snes->iter,snes->numLinearSolveFailures);CHKERRQ(ierr);
        snes->reason = SNES_DIVERGED_LINEAR_SOLVE;
        break;
      }
    }
    ierr = KSPGetIterationNumber(snes->ksp,&lits);CHKERRQ(ierr);
    snes->linear_its += lits;
    ierr = PetscInfo2(snes,"iter=%D, linear solve iterations=%D\n",snes->iter,lits);CHKERRQ(ierr);

    if (neP->precheckstep) {
      PetscTruth changed_y = PETSC_FALSE;
      ierr = (*neP->precheckstep)(snes,X,Y,neP->precheck,&changed_y);CHKERRQ(ierr);
    }

    if (PetscLogPrintInfo){
      ierr = SNESLSCheckResidual_Private(snes,snes->jacobian,F,Y,G,W);CHKERRQ(ierr);
    }

    /* Compute a (scaled) negative update in the line search routine: 
         Y <- X - lambda*Y 
       and evaluate G = function(Y) (depends on the line search). 
    */
    ierr = VecCopy(Y,snes->vec_sol_update);CHKERRQ(ierr);
    ynorm = 1; gnorm = fnorm;
    ierr = (*neP->LineSearch)(snes,neP->lsP,X,F,G,Y,W,fnorm,xnorm,&ynorm,&gnorm,&lssucceed);CHKERRQ(ierr);
    ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",fnorm,gnorm,ynorm,(int)lssucceed);CHKERRQ(ierr);
    if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
    if (!lssucceed) {
      if (++snes->numFailures >= snes->maxFailures) {
	PetscTruth ismin;
        snes->reason = SNES_DIVERGED_LS_FAILURE;
        ierr = SNESLSCheckLocalMin_Private(snes,snes->jacobian,G,W,gnorm,&ismin);CHKERRQ(ierr);
        if (ismin) snes->reason = SNES_DIVERGED_LOCAL_MIN;
        break;
      }
    }
    /* Update function and solution vectors */
    fnorm = gnorm;
    ierr = VecCopy(G,F);CHKERRQ(ierr);
    ierr = VecCopy(W,X);CHKERRQ(ierr);
    /* Monitor convergence */
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
    snes->iter = i+1;
    snes->norm = fnorm;
    ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
    SNESLogConvHistory(snes,snes->norm,lits);
    SNESMonitor(snes,snes->iter,snes->norm);
    /* Test for convergence, xnorm = || X || */
    if (snes->ops->converged != SNESSkipConverged) { ierr = VecNorm(X,NORM_2,&xnorm);CHKERRQ(ierr); }
    ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
    if (snes->reason) break;
  }
  if (i == maxits) {
    ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",maxits);CHKERRQ(ierr);
    if(!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
  }
  PetscFunctionReturn(0);
}
Beispiel #7
0
static PetscErrorCode SNESSolve_QN(SNES snes)
{
  PetscErrorCode      ierr;
  SNES_QN             *qn = (SNES_QN*) snes->data;
  Vec                 X,Xold;
  Vec                 F,B;
  Vec                 Y,FPC,D,Dold;
  SNESConvergedReason reason;
  PetscInt            i, i_r;
  PetscReal           fnorm,xnorm,ynorm,gnorm;
  PetscBool           lssucceed,powell,periodic;
  PetscScalar         DolddotD,DolddotDold,DdotD,YdotD;
  MatStructure        flg = DIFFERENT_NONZERO_PATTERN;

  /* basically just a regular newton's method except for the application of the jacobian */
  PetscFunctionBegin;

  F             = snes->vec_func;       /* residual vector */
  Y             = snes->vec_sol_update; /* search direction generated by J^-1D*/
  B             = snes->vec_rhs;

  X             = snes->vec_sol;        /* solution vector */
  Xold          = snes->work[0];

  /* directions generated by the preconditioned problem with F_pre = F or x - M(x, b) */
  D             = snes->work[1];
  Dold          = snes->work[2];

  snes->reason = SNES_CONVERGED_ITERATING;

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  if (!snes->vec_func_init_set){
    ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
  } else {
    snes->vec_func_init_set = PETSC_FALSE;
  }

  if (!snes->norm_init_set) {
    ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
    if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
  } else {
    fnorm = snes->norm_init;
    snes->norm_init_set = PETSC_FALSE;
  }

  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  SNESLogConvHistory(snes,fnorm,0);
  ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);

  /* set parameter for default relative tolerance convergence test */
   snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);

  /* composed solve */
  if (snes->pc && snes->pcside == PC_RIGHT) {
    ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr);
    ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr);
    ierr = SNESSolve(snes->pc, B, X);CHKERRQ(ierr);
    ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr);
    if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) {
      snes->reason = SNES_DIVERGED_INNER;
      PetscFunctionReturn(0);
    }
    ierr = SNESGetFunction(snes->pc, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr);
    ierr = VecCopy(FPC, F);CHKERRQ(ierr);
    ierr = SNESGetFunctionNorm(snes->pc, &fnorm);CHKERRQ(ierr);
    ierr = VecCopy(F, Y);CHKERRQ(ierr);
  } else {
    ierr = VecCopy(F, Y);CHKERRQ(ierr);
  }
  ierr = VecCopy(Y, D);CHKERRQ(ierr);

  /* scale the initial update */
  if (qn->scale_type == SNES_QN_SCALE_JACOBIAN) {
    ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);
  }

  for (i = 0, i_r = 0; i < snes->max_its; i++, i_r++) {
    switch(qn->type) {
    case SNES_QN_BADBROYDEN:
      ierr = SNESQNApply_BadBroyden(snes,i_r,Y,X,Xold,D,Dold);CHKERRQ(ierr);
      break;
    case SNES_QN_BROYDEN:
      ierr = SNESQNApply_Broyden(snes,i_r,Y,X,Xold,D,Dold);CHKERRQ(ierr);
      break;
    case SNES_QN_LBFGS:
      SNESQNApply_LBFGS(snes,i_r,Y,X,Xold,D,Dold);CHKERRQ(ierr);
      break;
    }
    /* line search for lambda */
    ynorm = 1; gnorm = fnorm;
    ierr = VecCopy(D, Dold);CHKERRQ(ierr);
    ierr = VecCopy(X, Xold);CHKERRQ(ierr);
    ierr = SNESLineSearchApply(snes->linesearch, X, F, &fnorm, Y);CHKERRQ(ierr);
    if (snes->reason == SNES_DIVERGED_FUNCTION_COUNT) break;
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
      }
    ierr = SNESLineSearchGetSuccess(snes->linesearch, &lssucceed);CHKERRQ(ierr);
    if (!lssucceed) {
      if (++snes->numFailures >= snes->maxFailures) {
        snes->reason = SNES_DIVERGED_LINE_SEARCH;
        break;
      }
    }
    ierr = SNESLineSearchGetNorms(snes->linesearch, &xnorm, &fnorm, &ynorm);CHKERRQ(ierr);
    if (qn->scale_type == SNES_QN_SCALE_LINESEARCH) {
      ierr = SNESLineSearchGetLambda(snes->linesearch, &qn->scaling);CHKERRQ(ierr);
    }

    /* convergence monitoring */
    ierr = PetscInfo4(snes,"fnorm=%18.16e, gnorm=%18.16e, ynorm=%18.16e, lssucceed=%d\n",(double)fnorm,(double)gnorm,(double)ynorm,(int)lssucceed);CHKERRQ(ierr);

    ierr = SNESSetIterationNumber(snes, i+1);CHKERRQ(ierr);
    ierr = SNESSetFunctionNorm(snes, fnorm);CHKERRQ(ierr);

    SNESLogConvHistory(snes,snes->norm,snes->iter);
    ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
    /* set parameter for default relative tolerance convergence test */
    ierr = (*snes->ops->converged)(snes,snes->iter,xnorm,ynorm,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
    if (snes->reason) PetscFunctionReturn(0);

    if (snes->pc && snes->pcside == PC_RIGHT) {
      ierr = SNESSetInitialFunction(snes->pc, F);CHKERRQ(ierr);
      ierr = SNESSetInitialFunctionNorm(snes->pc, fnorm);CHKERRQ(ierr);
      ierr = SNESSolve(snes->pc, B, X);CHKERRQ(ierr);
      ierr = SNESGetConvergedReason(snes->pc,&reason);CHKERRQ(ierr);
      if (reason < 0 && (reason != SNES_DIVERGED_MAX_IT)) {
        snes->reason = SNES_DIVERGED_INNER;
        PetscFunctionReturn(0);
      }
      ierr = SNESGetFunction(snes->pc, &FPC, PETSC_NULL, PETSC_NULL);CHKERRQ(ierr);
      ierr = VecCopy(FPC, F);CHKERRQ(ierr);
      ierr = SNESGetFunctionNorm(snes->pc, &fnorm);CHKERRQ(ierr);
      ierr = VecCopy(F, D);CHKERRQ(ierr);
    } else {
      ierr = VecCopy(F, D);CHKERRQ(ierr);
    }

    powell = PETSC_FALSE;
    if (qn->restart_type == SNES_QN_RESTART_POWELL) {
      /* check restart by Powell's Criterion: |F^T H_0 Fold| > 0.2 * |Fold^T H_0 Fold| */
      ierr = VecDotBegin(Dold, Dold, &DolddotDold);CHKERRQ(ierr);
      ierr = VecDotBegin(Dold, D, &DolddotD);CHKERRQ(ierr);
      ierr = VecDotBegin(D, D, &DdotD);CHKERRQ(ierr);
      ierr = VecDotBegin(Y, D, &YdotD);CHKERRQ(ierr);
      ierr = VecDotEnd(Dold, Dold, &DolddotDold);CHKERRQ(ierr);
      ierr = VecDotEnd(Dold, D, &DolddotD);CHKERRQ(ierr);
      ierr = VecDotEnd(D, D, &DdotD);CHKERRQ(ierr);
      ierr = VecDotEnd(Y, D, &YdotD);CHKERRQ(ierr);
      if (PetscAbs(PetscRealPart(DolddotD)) > qn->powell_gamma*PetscAbs(PetscRealPart(DolddotDold))) powell = PETSC_TRUE;
    }
    periodic = PETSC_FALSE;
    if (qn->restart_type == SNES_QN_RESTART_PERIODIC) {
      if (i_r>qn->m-1) periodic = PETSC_TRUE;
    }
    /* restart if either powell or periodic restart is satisfied. */
    if (powell || periodic) {
      if (qn->monitor) {
        ierr = PetscViewerASCIIAddTab(qn->monitor,((PetscObject)snes)->tablevel+2);CHKERRQ(ierr);
        ierr = PetscViewerASCIIPrintf(qn->monitor, "restart! |%14.12e| > %4.2f*|%14.12e| or i_r = %d\n", PetscRealPart(DolddotD), qn->powell_gamma, PetscRealPart(DolddotDold), i_r);CHKERRQ(ierr);
        ierr = PetscViewerASCIISubtractTab(qn->monitor,((PetscObject)snes)->tablevel+2);CHKERRQ(ierr);
      }
      i_r = -1;
      /* general purpose update */
      if (snes->ops->update) {
        ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
      }
      if (qn->scale_type == SNES_QN_SCALE_JACOBIAN) {
        ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);
      }
    }
    /* general purpose update */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }
  }
  if (i == snes->max_its) {
    ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", snes->max_its);CHKERRQ(ierr);
    if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
  }
  PetscFunctionReturn(0);
}
Beispiel #8
0
PetscErrorCode SNESSolve_Multiblock(SNES snes)
{
  SNES_Multiblock *mb = (SNES_Multiblock *) snes->data;
  Vec              X, Y, F;
  PetscReal        fnorm;
  PetscInt         maxits, i;
  PetscErrorCode   ierr;

  PetscFunctionBegin;
  snes->reason = SNES_CONVERGED_ITERATING;

  maxits = snes->max_its;        /* maximum number of iterations */
  X      = snes->vec_sol;        /* X^n */
  Y      = snes->vec_sol_update; /* \tilde X */
  F      = snes->vec_func;       /* residual vector */

  ierr = VecSetBlockSize(X, mb->bs);CHKERRQ(ierr);
  ierr = VecSetBlockSize(Y, mb->bs);CHKERRQ(ierr);
  ierr = VecSetBlockSize(F, mb->bs);CHKERRQ(ierr);
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);

  if (!snes->vec_func_init_set){
    ierr = SNESComputeFunction(snes, X, F);CHKERRQ(ierr);
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
  } else {
    snes->vec_func_init_set = PETSC_FALSE;
  }
  if (!snes->norm_init_set) {
    ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
    if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_FP, "Infinite or not-a-number generated in norm");
  } else {
    fnorm = snes->norm_init;
    snes->norm_init_set = PETSC_FALSE;
  }
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  SNESLogConvHistory(snes,fnorm,0);
  ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);

  /* set parameter for default relative tolerance convergence test */
  snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);

  for (i = 0; i < maxits; i++) {
    /* Call general purpose update function */
    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }
    /* Compute X^{new} from subsolves */
    if (mb->type == PC_COMPOSITE_ADDITIVE) {
      BlockDesc blocks = mb->blocks;

      if (mb->defaultblocks) {
        /*TODO: Make an array of Vecs for this */
        /*ierr = VecStrideGatherAll(X, mb->x, INSERT_VALUES);CHKERRQ(ierr);*/
        while (blocks) {
          ierr = SNESSolve(blocks->snes, PETSC_NULL, blocks->x);CHKERRQ(ierr);
          blocks = blocks->next;
        }
        /*ierr = VecStrideScatterAll(mb->x, X, INSERT_VALUES);CHKERRQ(ierr);*/
      } else {
        while (blocks) {
          ierr = VecScatterBegin(blocks->sctx, X, blocks->x, INSERT_VALUES, SCATTER_FORWARD);CHKERRQ(ierr);
          ierr = VecScatterEnd(blocks->sctx, X, blocks->x, INSERT_VALUES, SCATTER_FORWARD);CHKERRQ(ierr);
          ierr = SNESSolve(blocks->snes, PETSC_NULL, blocks->x);CHKERRQ(ierr);
          ierr = VecScatterBegin(blocks->sctx, blocks->x, X, INSERT_VALUES, SCATTER_REVERSE);CHKERRQ(ierr);
          ierr = VecScatterEnd(blocks->sctx, blocks->x, X, INSERT_VALUES, SCATTER_REVERSE);CHKERRQ(ierr);
          blocks = blocks->next;
        }
      }
    } else {
      SETERRQ1(((PetscObject) snes)->comm, PETSC_ERR_SUP, "Unsupported or unknown composition", (int) mb->type);
    }
    CHKMEMQ;
    /* Compute F(X^{new}) */
    ierr = SNESComputeFunction(snes, X, F);CHKERRQ(ierr);
    ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr);
    if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated norm");

    if (snes->nfuncs >= snes->max_funcs) {
      snes->reason = SNES_DIVERGED_FUNCTION_COUNT;
      break;
    }
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
    /* Monitor convergence */
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
    snes->iter = i+1;
    snes->norm = fnorm;
    ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
    SNESLogConvHistory(snes,snes->norm,0);
    ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
    /* Test for convergence */
    ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
    if (snes->reason) break;
  }
  if (i == maxits) {
    ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);CHKERRQ(ierr);
    if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
  }
  PetscFunctionReturn(0);
}
Beispiel #9
0
PetscErrorCode SNESSolve_FAS(SNES snes)
{
  PetscErrorCode ierr;
  PetscInt       i, maxits;
  Vec            X, F;
  PetscReal      fnorm;
  SNES_FAS       *fas = (SNES_FAS *)snes->data,*ffas;
  DM             dm;
  PetscBool      isFine;

  PetscFunctionBegin;
  maxits = snes->max_its;            /* maximum number of iterations */
  snes->reason = SNES_CONVERGED_ITERATING;
  X = snes->vec_sol;
  F = snes->vec_func;

  ierr = SNESFASCycleIsFine(snes, &isFine);CHKERRQ(ierr);
  /*norm setup */
  ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  snes->iter = 0;
  snes->norm = 0.;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  if (!snes->vec_func_init_set) {
    ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
    if (snes->domainerror) {
      snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
      PetscFunctionReturn(0);
    }
  } else {
    snes->vec_func_init_set = PETSC_FALSE;
  }

  if (!snes->norm_init_set) {
    ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
    if (PetscIsInfOrNanReal(fnorm)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_FP,"Infinite or not-a-number generated in norm");
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
  } else {
    fnorm = snes->norm_init;
    snes->norm_init_set = PETSC_FALSE;
  }

  snes->norm = fnorm;
  ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
  SNESLogConvHistory(snes,fnorm,0);
  ierr = SNESMonitor(snes,0,fnorm);CHKERRQ(ierr);

  /* set parameter for default relative tolerance convergence test */
  snes->ttol = fnorm*snes->rtol;
  /* test convergence */
  ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
  if (snes->reason) PetscFunctionReturn(0);


  if (isFine) {
    /* propagate scale-dependent data up the hierarchy */
    ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
    for (ffas=fas; ffas->next; ffas=(SNES_FAS*)ffas->next->data) {
      DM dmcoarse;
      ierr = SNESGetDM(ffas->next,&dmcoarse);CHKERRQ(ierr);
      ierr = DMRestrict(dm,ffas->restrct,ffas->rscale,ffas->inject,dmcoarse);CHKERRQ(ierr);
      dm = dmcoarse;
    }
  }

  for (i = 0; i < maxits; i++) {
    /* Call general purpose update function */

    if (snes->ops->update) {
      ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
    }
    if (fas->fastype == SNES_FAS_MULTIPLICATIVE) {
      ierr = SNESFASCycle_Multiplicative(snes, X);CHKERRQ(ierr);
    } else {
      ierr = SNESFASCycle_Additive(snes, X);CHKERRQ(ierr);
    }

    /* check for FAS cycle divergence */
    if (snes->reason != SNES_CONVERGED_ITERATING) {
      PetscFunctionReturn(0);
    }

    /* Monitor convergence */
    ierr = PetscObjectTakeAccess(snes);CHKERRQ(ierr);
    snes->iter = i+1;
    ierr = PetscObjectGrantAccess(snes);CHKERRQ(ierr);
    SNESLogConvHistory(snes,snes->norm,0);
    ierr = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
    /* Test for convergence */
    if (isFine) {
      ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,snes->norm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
      if (snes->reason) break;
    }
  }
  if (i == maxits) {
    ierr = PetscInfo1(snes, "Maximum number of iterations has been reached: %D\n", maxits);CHKERRQ(ierr);
    if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
  }
  PetscFunctionReturn(0);
}