petsc-master 2014-10-01
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ISCreateBlock

Creates a data structure for an index set containing a list of integers. The indices are relative to entries, not blocks.

Synopsis

#include "petscis.h"     
PetscErrorCode  ISCreateBlock(MPI_Comm comm,PetscInt bs,PetscInt n,const PetscInt idx[],PetscCopyMode mode,IS *is)
Collective on MPI_Comm

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 and count of block not indices
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()

Level:beginner
Location:
src/vec/is/is/impls/block/block.c
Index of all IS routines
Table of Contents for all manual pages
Index of all manual pages

Examples

src/vec/is/is/examples/tutorials/ex3.c.html
src/vec/is/is/examples/tutorials/ex3f90.F.html
src/dm/examples/tutorials/ex6.c.html