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_TRUE
if 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