ISBlockSetIndices#

Set integers representing blocks of indices in an index set of ISType ISBLOCK

Synopsis#

#include "petscis.h"     
PetscErrorCode ISBlockSetIndices(IS is, PetscInt bs, PetscInt n, const PetscInt idx[], PetscCopyMode mode)

Collective

Input Parameters#

  • is - the index set

  • bs - number of elements in each block

  • n - the length of the index set (the number of blocks)

  • idx - the list of integers, one for each block, the integers contain the index of the first index of each block divided by the block size

  • mode - see PetscCopyMode, only PETSC_COPY_VALUES and PETSC_OWN_POINTER are supported

Notes#

When the communicator is not MPI_COMM_SELF, the operations on the index sets, IS, are NOT conceptually the same as MPI_Group operations. The index sets are then distributed sets of indices and thus certain operations on them are collective.

The convenience routine ISCreateBlock() allows one to create the IS and provide the blocks in a single function call.

Example#

If you wish to index the values {0,1,4,5}, then use a block size of 2 and idx of {0,2}.

See Also#

Low-level Vector Communication, IS, ISCreateStride(), ISCreateGeneral(), ISAllGather(), ISCreateBlock(), ISBLOCK, ISGeneralSetIndices()

Level#

beginner

Location#

src/vec/is/is/impls/block/block.c

Implementations#

ISBlockSetIndices_Block in src/vec/is/is/impls/block/block.c

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