petsc-3.14.6 2021-03-30

ISOnComm

Split a parallel IS on subcomms (usually self) or concatenate index sets on subcomms into a parallel index set

#include "petscis.h" 
PetscErrorCode  ISOnComm(IS is,MPI_Comm comm,PetscCopyMode mode,IS *newis)

Collective on IS

	is	- index set
	comm	- communicator for new index set
	mode	- copy semantics, PETSC_USE_POINTER for no-copy if possible, otherwise PETSC_COPY_VALUES

newis

- new IS on comm

It is usually desirable to create a parallel IS and look at the local part when necessary.

This function is useful if serial ISs must be created independently, or to view many logically independent serial ISs.

The input IS must have the same type on every process.

advanced