1: /*
  2:   Code for manipulating distributed regular arrays in parallel.
  3: */

  5: #include <petsc/private/dmdaimpl.h>

  7: PetscErrorCode DMCreateGlobalVector_DA(DM da, Vec *g)
  8: {
  9:   DM_DA *dd = (DM_DA *)da->data;

 11:   PetscFunctionBegin;
 13:   PetscAssertPointer(g, 2);
 14:   PetscCall(VecCreate(PetscObjectComm((PetscObject)da), g));
 15:   PetscCall(VecSetSizes(*g, dd->Nlocal, PETSC_DETERMINE));
 16:   PetscCall(VecSetBlockSize(*g, dd->w));
 17:   PetscCall(VecSetType(*g, da->vectype));
 18:   if (dd->Nlocal < da->bind_below) {
 19:     PetscCall(VecSetBindingPropagates(*g, PETSC_TRUE));
 20:     PetscCall(VecBindToCPU(*g, PETSC_TRUE));
 21:   }
 22:   PetscCall(VecSetDM(*g, da));
 23:   PetscCall(VecSetLocalToGlobalMapping(*g, da->ltogmap));
 24:   PetscCall(VecSetOperation(*g, VECOP_VIEW, (void (*)(void))VecView_MPI_DA));
 25:   PetscCall(VecSetOperation(*g, VECOP_LOAD, (void (*)(void))VecLoad_Default_DA));
 26:   PetscFunctionReturn(PETSC_SUCCESS);
 27: }

 29: /*@
 30:   DMDACreateNaturalVector - Creates a parallel PETSc vector that
 31:   will hold vector values in the natural numbering, rather than in
 32:   the PETSc parallel numbering associated with the `DMDA`.

 34:   Collective

 36:   Input Parameter:
 37: . da - the `DMDA`

 39:   Output Parameter:
 40: . g - the distributed global vector

 42:   Level: advanced

 44:   Notes:
 45:   The natural numbering is a number of grid nodes that starts with, in three dimensions, with (0,0,0), (1,0,0), (2,0,0), ..., (m-1,0,0) followed by
 46:   (0,1,0), (1,1,0), (2,1,0), ..., (m,1,0) etc up to (0,n-1,p-1), (1,n-1,p-1), (2,n-1,p-1), ..., (m-1,n-1,p-1).

 48:   The output parameter, `g`, is a regular `Vec` that should be destroyed
 49:   with a call to `VecDestroy()` when usage is finished.

 51:   The number of local entries in the vector on each process is the same
 52:   as in a vector created with `DMCreateGlobalVector()`.

 54: .seealso: [](sec_struct), `DM`, `DMDA`, `DMDAGlobalToNaturalBegin()`, `DMDAGlobalToNaturalEnd()`, `DMDANaturalToGlobalBegin()`, `DMDANaturalToGlobalEnd()`,
 55:           `DMCreateLocalVector()`, `VecDuplicate()`, `VecDuplicateVecs()`, `DMDACreate1d()`, `DMDACreate2d()`, `DMDACreate3d()`, `DMGlobalToLocalBegin()`,
 56:           `DMGlobalToLocalEnd()`, `DMLocalToGlobalBegin()`
 57: @*/
 58: PetscErrorCode DMDACreateNaturalVector(DM da, Vec *g)
 59: {
 60:   PetscInt cnt;
 61:   DM_DA   *dd = (DM_DA *)da->data;

 63:   PetscFunctionBegin;
 65:   PetscAssertPointer(g, 2);
 66:   if (dd->natural) {
 67:     PetscCall(PetscObjectGetReference((PetscObject)dd->natural, &cnt));
 68:     if (cnt == 1) { /* object is not currently used by anyone */
 69:       PetscCall(PetscObjectReference((PetscObject)dd->natural));
 70:       *g = dd->natural;
 71:     } else PetscCall(VecDuplicate(dd->natural, g));
 72:   } else { /* create the first version of this guy */
 73:     PetscCall(VecCreate(PetscObjectComm((PetscObject)da), g));
 74:     PetscCall(VecSetSizes(*g, dd->Nlocal, PETSC_DETERMINE));
 75:     PetscCall(VecSetBlockSize(*g, dd->w));
 76:     PetscCall(VecSetType(*g, da->vectype));
 77:     PetscCall(PetscObjectReference((PetscObject)*g));
 78:     dd->natural = *g;
 79:   }
 80:   PetscFunctionReturn(PETSC_SUCCESS);
 81: }