Exemplo n.º 1
0
static PetscErrorCode PCSetFromOptions_Composite(PC pc)
{
  PC_Composite     *jac = (PC_Composite*)pc->data;
  PetscErrorCode   ierr;
  PetscInt         nmax = 8,i;
  PC_CompositeLink next;
  char             *pcs[8];
  PetscBool        flg;

  PetscFunctionBegin;
  ierr = PetscOptionsHead("Composite preconditioner options");CHKERRQ(ierr);
  ierr = PetscOptionsEnum("-pc_composite_type","Type of composition","PCCompositeSetType",PCCompositeTypes,(PetscEnum)jac->type,(PetscEnum*)&jac->type,&flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PCCompositeSetType(pc,jac->type);CHKERRQ(ierr);
  }
  ierr = PetscOptionsStringArray("-pc_composite_pcs","List of composite solvers","PCCompositeAddPC",pcs,&nmax,&flg);CHKERRQ(ierr);
  if (flg) {
    for (i=0; i<nmax; i++) {
      ierr = PCCompositeAddPC(pc,pcs[i]);CHKERRQ(ierr);
      ierr = PetscFree(pcs[i]);CHKERRQ(ierr);   /* deallocate string pcs[i], which is allocated in PetscOptionsStringArray() */
    }
  }
  ierr = PetscOptionsTail();CHKERRQ(ierr);

  next = jac->head;
  while (next) {
    ierr = PCSetFromOptions(next->pc);CHKERRQ(ierr);
    next = next->next;
  }
  PetscFunctionReturn(0);
}
Exemplo n.º 2
0
void setCompositePC(Type* A, PC pc) {
    PetscInt nsplits;
    KSP* subksp;
    PCFieldSplitGetSubKSP(pc, &nsplits, &subksp);
    if(A->_S.size() == 1)
        KSPSetOperators(subksp[nsplits - 1], A->_S[0], A->_S[0]);
    else {
        PC pcS;
        KSPGetPC(subksp[nsplits - 1], &pcS);
        for(int i = 0; i < A->_S.size(); ++i)
            PCCompositeAddPC(pcS, PCNONE);
        PCSetUp(pcS);
        for(int i = 0; i < A->_S.size(); ++i) {
            PC subpc;
            PCCompositeGetPC(pcS, i, &subpc);
            PCSetOperators(subpc, A->_S[i], A->_S[i]);
            PCSetFromOptions(subpc);
        }
    }
    PetscFree(subksp);
}
Exemplo n.º 3
0
int main(int argc, char **argv)
{
  PetscErrorCode ierr;
  PetscInt       n=10000,its,dfid=1;
  Vec            x,b,u;
  Mat            A;
  KSP            ksp;
  PC             pc,pcnoise;
  PCNoise_Ctx    ctx={0,NULL};
  PetscReal      eta=0.1,norm;
  PetscScalar(*diagfunc)(PetscInt,PetscInt);

  ierr = PetscInitialize(&argc,&argv,(char*)0,help);CHKERRQ(ierr);

  /* Process command line options */
  ierr = PetscOptionsGetInt(NULL,"-n",&n,NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetReal(NULL,"-eta",&eta,NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetInt(NULL,"-diagfunc",&dfid,NULL);CHKERRQ(ierr);
  switch(dfid){
    case 1:
      diagfunc = diagFunc1;
      break;
    case 2:
      diagfunc = diagFunc2;
      break;
    case 3:
      diagfunc = diagFunc3;
      break;
    default:
      SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Unrecognized diagfunc option");
  }

  /* Create a diagonal matrix with a given distribution of diagonal elements */
  ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
  ierr = MatSetSizes(A,PETSC_DECIDE,PETSC_DECIDE,n,n);CHKERRQ(ierr);
  ierr = MatSetFromOptions(A);CHKERRQ(ierr);
  ierr = MatSetUp(A);CHKERRQ(ierr);
  ierr = AssembleDiagonalMatrix(A,diagfunc);CHKERRQ(ierr);

  /* Allocate vectors and manufacture an exact solution and rhs */
  ierr = MatCreateVecs(A,&x,NULL);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject)x,"Computed Solution");CHKERRQ(ierr);
  ierr = MatCreateVecs(A,&b,NULL);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject)b,"RHS");CHKERRQ(ierr);
  ierr = MatCreateVecs(A,&u,NULL);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject)u,"Reference Solution");CHKERRQ(ierr);
  ierr = VecSet(u,1.0);CHKERRQ(ierr);
  ierr = MatMult(A,u,b);CHKERRQ(ierr);

  /* Create a KSP object */
  ierr = KSPCreate(PETSC_COMM_WORLD,&ksp);CHKERRQ(ierr);
  ierr = KSPSetOperators(ksp,A,A);CHKERRQ(ierr);

  /* Set up a composite preconditioner */
  ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
  ierr = PCSetType(pc,PCCOMPOSITE);CHKERRQ(ierr); /* default composite with single Identity PC */
  ierr = PCCompositeSetType(pc,PC_COMPOSITE_ADDITIVE);CHKERRQ(ierr);
  ierr = PCCompositeAddPC(pc,PCNONE);CHKERRQ(ierr);
  if(eta > 0){
    ierr = PCCompositeAddPC(pc,PCSHELL);CHKERRQ(ierr);
    ierr = PCCompositeGetPC(pc,1,&pcnoise);CHKERRQ(ierr);
    ctx.eta = eta;
    ierr = PCShellSetContext(pcnoise,&ctx);CHKERRQ(ierr);
    ierr = PCShellSetApply(pcnoise,PCApply_Noise);CHKERRQ(ierr);
    ierr = PCShellSetSetUp(pcnoise,PCSetup_Noise);CHKERRQ(ierr);
    ierr = PCShellSetDestroy(pcnoise,PCDestroy_Noise);CHKERRQ(ierr);
    ierr = PCShellSetName(pcnoise,"Noise PC");CHKERRQ(ierr);
  }

  /* Set KSP from options (this can override the PC just defined) */
  ierr = KSPSetFromOptions(ksp);CHKERRQ(ierr);

  /* Solve */
  ierr = KSPSolve(ksp,b,x);CHKERRQ(ierr);

  /* Compute error */
  ierr = VecAXPY(x,-1.0,u);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject)x,"Error");CHKERRQ(ierr);
  ierr = VecNorm(x,NORM_2,&norm);CHKERRQ(ierr);
  ierr = KSPGetIterationNumber(ksp,&its);CHKERRQ(ierr);
  ierr = PetscPrintf(PETSC_COMM_WORLD,"Norm of error %g, Iterations %D\n",(double)norm,its);CHKERRQ(ierr);

  /* Destroy objects and finalize */
  ierr = KSPDestroy(&ksp);CHKERRQ(ierr);
  ierr = MatDestroy(&A);CHKERRQ(ierr);
  ierr = VecDestroy(&x);CHKERRQ(ierr);
  ierr = VecDestroy(&b);CHKERRQ(ierr);
  ierr = VecDestroy(&u);CHKERRQ(ierr);
  PetscFinalize();

  return 0;
}
Exemplo n.º 4
0
#include <petsc/private/fortranimpl.h>
#include <petscpc.h>

#if defined(PETSC_HAVE_FORTRAN_CAPS)
#define pccompositeaddpc_          PCCOMPOSITEADDPC
#elif !defined(PETSC_HAVE_FORTRAN_UNDERSCORE)
#define pccompositeaddpc_          pccompositeaddpc
#endif

PETSC_EXTERN void PETSC_STDCALL pccompositeaddpc_(PC *pc,CHAR type PETSC_MIXED_LEN(len),PetscErrorCode *ierr PETSC_END_LEN(len))
{
  char *t;

  FIXCHAR(type,len,t);
  *ierr = PCCompositeAddPC(*pc,t);
  FREECHAR(type,t);
}