PETSC_COMM_WORLD

the equivalent of the MPI_COMM_WORLD communicator which represents all the processes that PETSc knows about.

Notes

By default PETSC_COMM_WORLD and MPI_COMM_WORLD are identical unless you wish to run PETSc on ONLY a subset of MPI_COMM_WORLD. In that case create your new (smaller) communicator, call it, say comm, and set PETSC_COMM_WORLD = comm BEFORE calling PetscInitialize(), but after MPI_Init() has been called.

The value of PETSC_COMM_WORLD should never be used or accessed before PetscInitialize() is called because it may not have a valid value yet.

See Also

PETSC_COMM_SELF

Level

beginner

Location

include/petscsys.h

Examples

src/tao/leastsquares/tutorials/chwirut2.c
src/mat/tutorials/ex7.c
src/mat/tutorials/ex10.c
src/mat/tutorials/ex12.c
src/mat/tutorials/ex19.c
src/mat/tutorials/ex1.c
src/mat/tutorials/ex18.c
src/mat/tutorials/ex11.c
src/mat/tutorials/ex16.c

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Index of all Sys routines
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Index of all manual pages