petsc-3.7.7 2017-09-25

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}.

Examples

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