ISCreateBlock#
Creates a data structure for an index set containing a list of integers. Each integer represents a fixed block size set of indices.
Synopsis#
#include "petscis.h"
PetscErrorCode ISCreateBlock(MPI_Comm comm, PetscInt bs, PetscInt n, const PetscInt idx[], PetscCopyMode mode, IS *is)
Collective
Input Parameters#
comm - the MPI communicator
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 entry of each block divided by the block size
mode - see PetscCopyMode, only PETSC_COPY_VALUES and PETSC_OWN_POINTER are supported in this routine
Output Parameter#
is - the new index set
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.
Example#
If you wish to index the values {0,1,6,7}, then use a block size of 2 and idx of {0,3}.
See Also#
ISCreateStride()
, ISCreateGeneral()
, ISAllGather()
, ISBlockSetIndices()
, ISBLOCK
, ISGENERAL
Level#
beginner
Location#
Examples#
src/vec/vec/utils/tagger/tutorials/ex1.c.html
src/vec/is/is/tutorials/ex3.c.html
src/vec/is/is/tutorials/ex3f90.F90.html
src/ksp/ksp/tutorials/ex71.c.html
Index of all IS routines
Table of Contents for all manual pages
Index of all manual pages