petsc-3.14.6 2021-03-30

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

- 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}.

Level

beginner

Location

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

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