ISIdentity#
Determines whether index set is the identity mapping.
Synopsis#
#include "petscis.h"
PetscErrorCode ISIdentity(IS is, PetscBool *ident)
Collective
Input Parameter#
is - the index set
Output Parameter#
ident -
PETSC_TRUEif an identity, elsePETSC_FALSE
Note#
If ISSetIdentity() (or ISSetInfo() for a permanent property) has been called,
ISIdentity() will return its answer without communication between processes, but
otherwise the output ident will be computed from ISGetInfo(),
which may require synchronization on the communicator of is. To avoid this computation,
call ISGetInfo() directly with the compute flag set to PETSC_FALSE, and ident will be assumed false.
See Also#
IS, ISSetIdentity(), ISGetInfo()
Level#
intermediate
Location#
src/vec/is/is/interface/index.c
Index of all IS routines
Table of Contents for all manual pages
Index of all manual pages