petsc-3.14.5 2021-03-03
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# PetscSplitOwnership

Given a global (or local) length determines a local (or global) length via a simple formula

### Synopsis

    #include "petscsys.h"
    PetscErrorCode  PetscSplitOwnership(MPI_Comm comm,PetscInt *n,PetscInt *N)

Collective (if n or N is PETSC_DECIDE)

### Input Parameters

| comm | - MPI communicator that shares the object being divided
| n | - local length (or PETSC_DECIDE to have it set)
| N | - global length (or PETSC_DECIDE)

### Notes

n and N cannot be both PETSC_DECIDE

If one processor calls this with n or N of PETSC_DECIDE then all processors must. Otherwise, an error is thrown in debug mode while the program will hang in optimized (i.e. configured --with-debugging=0) mode.

### See Also

PetscSplitOwnershipBlock()

### Level

developer

### Location

src/sys/utils/psplit.c
Index of all Sys routines
Table of Contents for all manual pages
Index of all manual pages