Example #1
0
File: mg.c Project: ziolai/petsc
PetscErrorCode PCSetUp_MG(PC pc)
{
  PC_MG          *mg        = (PC_MG*)pc->data;
  PC_MG_Levels   **mglevels = mg->levels;
  PetscErrorCode ierr;
  PetscInt       i,n = mglevels[0]->levels;
  PC             cpc;
  PetscBool      dump = PETSC_FALSE,opsset,use_amat,missinginterpolate = PETSC_FALSE;
  Mat            dA,dB;
  Vec            tvec;
  DM             *dms;
  PetscViewer    viewer = 0;

  PetscFunctionBegin;
  /* FIX: Move this to PCSetFromOptions_MG? */
  if (mg->usedmfornumberoflevels) {
    PetscInt levels;
    ierr = DMGetRefineLevel(pc->dm,&levels);CHKERRQ(ierr);
    levels++;
    if (levels > n) { /* the problem is now being solved on a finer grid */
      ierr     = PCMGSetLevels(pc,levels,NULL);CHKERRQ(ierr);
      n        = levels;
      ierr     = PCSetFromOptions(pc);CHKERRQ(ierr); /* it is bad to call this here, but otherwise will never be called for the new hierarchy */
      mglevels =  mg->levels;
    }
  }
  ierr = KSPGetPC(mglevels[0]->smoothd,&cpc);CHKERRQ(ierr);


  /* If user did not provide fine grid operators OR operator was not updated since last global KSPSetOperators() */
  /* so use those from global PC */
  /* Is this what we always want? What if user wants to keep old one? */
  ierr = KSPGetOperatorsSet(mglevels[n-1]->smoothd,NULL,&opsset);CHKERRQ(ierr);
  if (opsset) {
    Mat mmat;
    ierr = KSPGetOperators(mglevels[n-1]->smoothd,NULL,&mmat);CHKERRQ(ierr);
    if (mmat == pc->pmat) opsset = PETSC_FALSE;
  }

  if (!opsset) {
    ierr = PCGetUseAmat(pc,&use_amat);CHKERRQ(ierr);
    if(use_amat){
      ierr = PetscInfo(pc,"Using outer operators to define finest grid operator \n  because PCMGGetSmoother(pc,nlevels-1,&ksp);KSPSetOperators(ksp,...); was not called.\n");CHKERRQ(ierr);
      ierr = KSPSetOperators(mglevels[n-1]->smoothd,pc->mat,pc->pmat);CHKERRQ(ierr);
    }
    else {
      ierr = PetscInfo(pc,"Using matrix (pmat) operators to define finest grid operator \n  because PCMGGetSmoother(pc,nlevels-1,&ksp);KSPSetOperators(ksp,...); was not called.\n");CHKERRQ(ierr);
      ierr = KSPSetOperators(mglevels[n-1]->smoothd,pc->pmat,pc->pmat);CHKERRQ(ierr);
    }
  }

  for (i=n-1; i>0; i--) {
    if (!(mglevels[i]->interpolate || mglevels[i]->restrct)) {
      missinginterpolate = PETSC_TRUE;
      continue;
    }
  }
  /*
   Skipping if user has provided all interpolation/restriction needed (since DM might not be able to produce them (when coming from SNES/TS)
   Skipping for galerkin==2 (externally managed hierarchy such as ML and GAMG). Cleaner logic here would be great. Wrap ML/GAMG as DMs?
  */
  if (missinginterpolate && pc->dm && mg->galerkin != 2 && !pc->setupcalled) {
    /* construct the interpolation from the DMs */
    Mat p;
    Vec rscale;
    ierr     = PetscMalloc1(n,&dms);CHKERRQ(ierr);
    dms[n-1] = pc->dm;
    /* Separately create them so we do not get DMKSP interference between levels */
    for (i=n-2; i>-1; i--) {ierr = DMCoarsen(dms[i+1],MPI_COMM_NULL,&dms[i]);CHKERRQ(ierr);}
    for (i=n-2; i>-1; i--) {
      DMKSP     kdm;
      PetscBool dmhasrestrict;
      ierr = KSPSetDM(mglevels[i]->smoothd,dms[i]);CHKERRQ(ierr);
      if (mg->galerkin) {ierr = KSPSetDMActive(mglevels[i]->smoothd,PETSC_FALSE);CHKERRQ(ierr);}
      ierr = DMGetDMKSPWrite(dms[i],&kdm);CHKERRQ(ierr);
      /* Ugly hack so that the next KSPSetUp() will use the RHS that we set. A better fix is to change dmActive to take
       * a bitwise OR of computing the matrix, RHS, and initial iterate. */
      kdm->ops->computerhs = NULL;
      kdm->rhsctx          = NULL;
      if (!mglevels[i+1]->interpolate) {
        ierr = DMCreateInterpolation(dms[i],dms[i+1],&p,&rscale);CHKERRQ(ierr);
        ierr = PCMGSetInterpolation(pc,i+1,p);CHKERRQ(ierr);
        if (rscale) {ierr = PCMGSetRScale(pc,i+1,rscale);CHKERRQ(ierr);}
        ierr = VecDestroy(&rscale);CHKERRQ(ierr);
        ierr = MatDestroy(&p);CHKERRQ(ierr);
      }
      ierr = DMHasCreateRestriction(dms[i],&dmhasrestrict);CHKERRQ(ierr);
      if (dmhasrestrict && !mglevels[i+1]->restrct){
        ierr = DMCreateRestriction(dms[i],dms[i+1],&p);CHKERRQ(ierr);
        ierr = PCMGSetRestriction(pc,i+1,p);CHKERRQ(ierr);
        ierr = MatDestroy(&p);CHKERRQ(ierr);
      }
    }

    for (i=n-2; i>-1; i--) {ierr = DMDestroy(&dms[i]);CHKERRQ(ierr);}
    ierr = PetscFree(dms);CHKERRQ(ierr);
  }

  if (pc->dm && !pc->setupcalled) {
    /* finest smoother also gets DM but it is not active, independent of whether galerkin==2 */
    ierr = KSPSetDM(mglevels[n-1]->smoothd,pc->dm);CHKERRQ(ierr);
    ierr = KSPSetDMActive(mglevels[n-1]->smoothd,PETSC_FALSE);CHKERRQ(ierr);
  }

  if (mg->galerkin == 1) {
    Mat B;
    /* currently only handle case where mat and pmat are the same on coarser levels */
    ierr = KSPGetOperators(mglevels[n-1]->smoothd,&dA,&dB);CHKERRQ(ierr);
    if (!pc->setupcalled) {
      for (i=n-2; i>-1; i--) {
        if (!mglevels[i+1]->restrct && !mglevels[i+1]->interpolate) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must provide interpolation or restriction for each MG level except level 0");
        if (!mglevels[i+1]->interpolate) {
          ierr = PCMGSetInterpolation(pc,i+1,mglevels[i+1]->restrct);CHKERRQ(ierr);
        }
        if (!mglevels[i+1]->restrct) {
          ierr = PCMGSetRestriction(pc,i+1,mglevels[i+1]->interpolate);CHKERRQ(ierr);
        }
        if (mglevels[i+1]->interpolate == mglevels[i+1]->restrct) {
          ierr = MatPtAP(dB,mglevels[i+1]->interpolate,MAT_INITIAL_MATRIX,1.0,&B);CHKERRQ(ierr);
        } else {
          ierr = MatMatMatMult(mglevels[i+1]->restrct,dB,mglevels[i+1]->interpolate,MAT_INITIAL_MATRIX,1.0,&B);CHKERRQ(ierr);
        }
        ierr = KSPSetOperators(mglevels[i]->smoothd,B,B);CHKERRQ(ierr);
        if (i != n-2) {ierr = PetscObjectDereference((PetscObject)dB);CHKERRQ(ierr);}
        dB = B;
      }
      if (n > 1) {ierr = PetscObjectDereference((PetscObject)dB);CHKERRQ(ierr);}
    } else {
      for (i=n-2; i>-1; i--) {
        if (!mglevels[i+1]->restrct && !mglevels[i+1]->interpolate) SETERRQ(PetscObjectComm((PetscObject)pc),PETSC_ERR_ARG_WRONGSTATE,"Must provide interpolation or restriction for each MG level except level 0");
        if (!mglevels[i+1]->interpolate) {
          ierr = PCMGSetInterpolation(pc,i+1,mglevels[i+1]->restrct);CHKERRQ(ierr);
        }
        if (!mglevels[i+1]->restrct) {
          ierr = PCMGSetRestriction(pc,i+1,mglevels[i+1]->interpolate);CHKERRQ(ierr);
        }
        ierr = KSPGetOperators(mglevels[i]->smoothd,NULL,&B);CHKERRQ(ierr);
        if (mglevels[i+1]->interpolate == mglevels[i+1]->restrct) {
          ierr = MatPtAP(dB,mglevels[i+1]->interpolate,MAT_REUSE_MATRIX,1.0,&B);CHKERRQ(ierr);
        } else {
          ierr = MatMatMatMult(mglevels[i+1]->restrct,dB,mglevels[i+1]->interpolate,MAT_REUSE_MATRIX,1.0,&B);CHKERRQ(ierr);
        }
        ierr = KSPSetOperators(mglevels[i]->smoothd,B,B);CHKERRQ(ierr);
        dB   = B;
      }
    }
  } else if (!mg->galerkin && pc->dm && pc->dm->x) {
    /* need to restrict Jacobian location to coarser meshes for evaluation */
    for (i=n-2; i>-1; i--) {
      Mat R;
      Vec rscale;
      if (!mglevels[i]->smoothd->dm->x) {
        Vec *vecs;
        ierr = KSPCreateVecs(mglevels[i]->smoothd,1,&vecs,0,NULL);CHKERRQ(ierr);
        mglevels[i]->smoothd->dm->x = vecs[0];
        ierr = PetscFree(vecs);CHKERRQ(ierr);
      }
      ierr = PCMGGetRestriction(pc,i+1,&R);CHKERRQ(ierr);
      ierr = PCMGGetRScale(pc,i+1,&rscale);CHKERRQ(ierr);
      ierr = MatRestrict(R,mglevels[i+1]->smoothd->dm->x,mglevels[i]->smoothd->dm->x);CHKERRQ(ierr);
      ierr = VecPointwiseMult(mglevels[i]->smoothd->dm->x,mglevels[i]->smoothd->dm->x,rscale);CHKERRQ(ierr);
    }
  }
  if (!mg->galerkin && pc->dm) {
    for (i=n-2; i>=0; i--) {
      DM  dmfine,dmcoarse;
      Mat Restrict,Inject;
      Vec rscale;
      ierr   = KSPGetDM(mglevels[i+1]->smoothd,&dmfine);CHKERRQ(ierr);
      ierr   = KSPGetDM(mglevels[i]->smoothd,&dmcoarse);CHKERRQ(ierr);
      ierr   = PCMGGetRestriction(pc,i+1,&Restrict);CHKERRQ(ierr);
      ierr   = PCMGGetRScale(pc,i+1,&rscale);CHKERRQ(ierr);
      Inject = NULL;      /* Callback should create it if it needs Injection */
      ierr   = DMRestrict(dmfine,Restrict,rscale,Inject,dmcoarse);CHKERRQ(ierr);
    }
  }

  if (!pc->setupcalled) {
    for (i=0; i<n; i++) {
      ierr = KSPSetFromOptions(mglevels[i]->smoothd);CHKERRQ(ierr);
    }
    for (i=1; i<n; i++) {
      if (mglevels[i]->smoothu && (mglevels[i]->smoothu != mglevels[i]->smoothd)) {
        ierr = KSPSetFromOptions(mglevels[i]->smoothu);CHKERRQ(ierr);
      }
    }
    /* insure that if either interpolation or restriction is set the other other one is set */
    for (i=1; i<n; i++) {
      ierr = PCMGGetInterpolation(pc,i,NULL);CHKERRQ(ierr);
      ierr = PCMGGetRestriction(pc,i,NULL);CHKERRQ(ierr);
    }
    for (i=0; i<n-1; i++) {
      if (!mglevels[i]->b) {
        Vec *vec;
        ierr = KSPCreateVecs(mglevels[i]->smoothd,1,&vec,0,NULL);CHKERRQ(ierr);
        ierr = PCMGSetRhs(pc,i,*vec);CHKERRQ(ierr);
        ierr = VecDestroy(vec);CHKERRQ(ierr);
        ierr = PetscFree(vec);CHKERRQ(ierr);
      }
      if (!mglevels[i]->r && i) {
        ierr = VecDuplicate(mglevels[i]->b,&tvec);CHKERRQ(ierr);
        ierr = PCMGSetR(pc,i,tvec);CHKERRQ(ierr);
        ierr = VecDestroy(&tvec);CHKERRQ(ierr);
      }
      if (!mglevels[i]->x) {
        ierr = VecDuplicate(mglevels[i]->b,&tvec);CHKERRQ(ierr);
        ierr = PCMGSetX(pc,i,tvec);CHKERRQ(ierr);
        ierr = VecDestroy(&tvec);CHKERRQ(ierr);
      }
    }
    if (n != 1 && !mglevels[n-1]->r) {
      /* PCMGSetR() on the finest level if user did not supply it */
      Vec *vec;
      ierr = KSPCreateVecs(mglevels[n-1]->smoothd,1,&vec,0,NULL);CHKERRQ(ierr);
      ierr = PCMGSetR(pc,n-1,*vec);CHKERRQ(ierr);
      ierr = VecDestroy(vec);CHKERRQ(ierr);
      ierr = PetscFree(vec);CHKERRQ(ierr);
    }
  }

  if (pc->dm) {
    /* need to tell all the coarser levels to rebuild the matrix using the DM for that level */
    for (i=0; i<n-1; i++) {
      if (mglevels[i]->smoothd->setupstage != KSP_SETUP_NEW) mglevels[i]->smoothd->setupstage = KSP_SETUP_NEWMATRIX;
    }
  }

  for (i=1; i<n; i++) {
    if (mglevels[i]->smoothu == mglevels[i]->smoothd || mg->am == PC_MG_FULL || mg->am == PC_MG_KASKADE || mg->cyclesperpcapply > 1){
      /* if doing only down then initial guess is zero */
      ierr = KSPSetInitialGuessNonzero(mglevels[i]->smoothd,PETSC_TRUE);CHKERRQ(ierr);
    }
    if (mglevels[i]->eventsmoothsetup) {ierr = PetscLogEventBegin(mglevels[i]->eventsmoothsetup,0,0,0,0);CHKERRQ(ierr);}
    ierr = KSPSetUp(mglevels[i]->smoothd);CHKERRQ(ierr);
    if (mglevels[i]->smoothd->reason == KSP_DIVERGED_PCSETUP_FAILED) {
      pc->failedreason = PC_SUBPC_ERROR;
    }
    if (mglevels[i]->eventsmoothsetup) {ierr = PetscLogEventEnd(mglevels[i]->eventsmoothsetup,0,0,0,0);CHKERRQ(ierr);}
    if (!mglevels[i]->residual) {
      Mat mat;
      ierr = KSPGetOperators(mglevels[i]->smoothd,NULL,&mat);CHKERRQ(ierr);
      ierr = PCMGSetResidual(pc,i,PCMGResidualDefault,mat);CHKERRQ(ierr);
    }
  }
  for (i=1; i<n; i++) {
    if (mglevels[i]->smoothu && mglevels[i]->smoothu != mglevels[i]->smoothd) {
      Mat          downmat,downpmat;

      /* check if operators have been set for up, if not use down operators to set them */
      ierr = KSPGetOperatorsSet(mglevels[i]->smoothu,&opsset,NULL);CHKERRQ(ierr);
      if (!opsset) {
        ierr = KSPGetOperators(mglevels[i]->smoothd,&downmat,&downpmat);CHKERRQ(ierr);
        ierr = KSPSetOperators(mglevels[i]->smoothu,downmat,downpmat);CHKERRQ(ierr);
      }

      ierr = KSPSetInitialGuessNonzero(mglevels[i]->smoothu,PETSC_TRUE);CHKERRQ(ierr);
      if (mglevels[i]->eventsmoothsetup) {ierr = PetscLogEventBegin(mglevels[i]->eventsmoothsetup,0,0,0,0);CHKERRQ(ierr);}
      ierr = KSPSetUp(mglevels[i]->smoothu);CHKERRQ(ierr);
      if (mglevels[i]->smoothu->reason == KSP_DIVERGED_PCSETUP_FAILED) {
        pc->failedreason = PC_SUBPC_ERROR;
      }
      if (mglevels[i]->eventsmoothsetup) {ierr = PetscLogEventEnd(mglevels[i]->eventsmoothsetup,0,0,0,0);CHKERRQ(ierr);}
    }
  }

  if (mglevels[0]->eventsmoothsetup) {ierr = PetscLogEventBegin(mglevels[0]->eventsmoothsetup,0,0,0,0);CHKERRQ(ierr);}
  ierr = KSPSetUp(mglevels[0]->smoothd);CHKERRQ(ierr);
  if (mglevels[0]->smoothd->reason == KSP_DIVERGED_PCSETUP_FAILED) {
    pc->failedreason = PC_SUBPC_ERROR;
  }
  if (mglevels[0]->eventsmoothsetup) {ierr = PetscLogEventEnd(mglevels[0]->eventsmoothsetup,0,0,0,0);CHKERRQ(ierr);}

  /*
     Dump the interpolation/restriction matrices plus the
   Jacobian/stiffness on each level. This allows MATLAB users to
   easily check if the Galerkin condition A_c = R A_f R^T is satisfied.

   Only support one or the other at the same time.
  */
#if defined(PETSC_USE_SOCKET_VIEWER)
  ierr = PetscOptionsGetBool(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_mg_dump_matlab",&dump,NULL);CHKERRQ(ierr);
  if (dump) viewer = PETSC_VIEWER_SOCKET_(PetscObjectComm((PetscObject)pc));
  dump = PETSC_FALSE;
#endif
  ierr = PetscOptionsGetBool(((PetscObject)pc)->options,((PetscObject)pc)->prefix,"-pc_mg_dump_binary",&dump,NULL);CHKERRQ(ierr);
  if (dump) viewer = PETSC_VIEWER_BINARY_(PetscObjectComm((PetscObject)pc));

  if (viewer) {
    for (i=1; i<n; i++) {
      ierr = MatView(mglevels[i]->restrct,viewer);CHKERRQ(ierr);
    }
    for (i=0; i<n; i++) {
      ierr = KSPGetPC(mglevels[i]->smoothd,&pc);CHKERRQ(ierr);
      ierr = MatView(pc->mat,viewer);CHKERRQ(ierr);
    }
  }
  PetscFunctionReturn(0);
}
Example #2
0
PETSC_EXTERN void PETSC_STDCALL  pcmggetrscale_(PC pc,PetscInt *l,Vec *rscale, int *__ierr ){
*__ierr = PCMGGetRScale(
	(PC)PetscToPointer((pc) ),*l,rscale);
}