1: /*
  2:    This file contains routines for Parallel vector operations.
  3:  */

  5: #include <petscvec.h>

  7: /*@
  8:   VecCreateMPI - Creates a parallel vector.

 10:   Collective

 12:   Input Parameters:
 13: + comm - the MPI communicator to use
 14: . n    - local vector length (or `PETSC_DECIDE` to have calculated if `N` is given)
 15: - N    - global vector length (or `PETSC_DETERMINE` to have calculated if `n` is given)

 17:   Output Parameter:
 18: . v - the vector

 20:   Level: intermediate

 22:   Notes:
 23:   It is recommended to use `VecCreateFromOptions()` instead of this routine

 25:   Use `VecDuplicate()` or `VecDuplicateVecs()` to form additional vectors of the
 26:   same type as an existing vector.

 28:   If `n` is not `PETSC_DECIDE`, then the value determines the `PetscLayout` of the vector and the ranges returned by
 29:   `VecGetOwnershipRange()` and `VecGetOwnershipRanges()`

 31: .seealso: [](ch_vectors), `Vec`, `VecType`, `VecCreateSeq()`, `VecCreate()`, `VecDuplicate()`, `VecDuplicateVecs()`, `VecCreateGhost()`,
 32:           `VecCreateMPIWithArray()`, `VecCreateGhostWithArray()`, `VecMPISetGhost()`, `PetscLayout`,
 33:           `VecGetOwnershipRange()`, `VecGetOwnershipRanges()`
 34: @*/
 35: PetscErrorCode VecCreateMPI(MPI_Comm comm, PetscInt n, PetscInt N, Vec *v)
 36: {
 37:   PetscFunctionBegin;
 38:   PetscCall(VecCreate(comm, v));
 39:   PetscCall(VecSetSizes(*v, n, N));
 40:   PetscCall(VecSetType(*v, VECMPI));
 41:   PetscFunctionReturn(PETSC_SUCCESS);
 42: }