PetscViewerGetSubViewer#
Creates a new PetscViewer
(same type as the old) that lives on a subcommunicator of the original viewer’s communicator
Synopsis#
#include "petscviewer.h"
PetscErrorCode PetscViewerGetSubViewer(PetscViewer viewer, MPI_Comm comm, PetscViewer *outviewer)
Collective
Input Parameter#
viewer - the
PetscViewer
to be reproduced
Output Parameter#
outviewer - new
PetscViewer
Notes#
The output of the subviewers is synchronized against the original viewer. For example, if a
viewer on two MPI processes is decomposed into two subviewers, the output from the first viewer is
all printed before the output from the second viewer. You must call PetscViewerFlush()
after
the call to PetscViewerRestoreSubViewer()
.
Call PetscViewerRestoreSubViewer()
to destroy this PetscViewer
, NOT PetscViewerDestroy()
This is most commonly used to view a sequential object that is part of a
parallel object. For example PCView()
on a PCBJACOBI
could use this to obtain a
PetscViewer
that is used with the sequential KSP
on one block of the preconditioner.
Between the calls to PetscViewerGetSubViewer()
and PetscViewerRestoreSubViewer()
the original
viewer should not be used
PETSCVIEWERDRAW
and PETSCVIEWERBINARY
only support returning a singleton viewer on MPI rank 0,
all other ranks will return a NULL
viewer
Developer Notes#
There is currently incomplete error checking to ensure the user does not use the original viewer between the
the calls to PetscViewerGetSubViewer()
and PetscViewerRestoreSubViewer()
. If the user does there
could be errors in the viewing that go undetected or crash the code.
It would be nice if the call to PetscViewerFlush()
was not required and was handled by
PetscViewerRestoreSubViewer()
See Also#
Viewers: Looking at PETSc Objects, PetscViewer
, PetscViewerSocketOpen()
, PetscViewerASCIIOpen()
, PetscViewerDrawOpen()
, PetscViewerRestoreSubViewer()
Level#
advanced
Location#
Examples#
src/dm/tutorials/ex6.c
src/vec/vec/tutorials/ex14f.F90
src/vec/vec/tutorials/ex9f.F90
Implementations#
PetscViewerGetSubViewer_ASCII in src/sys/classes/viewer/impls/ascii/filev.c
PetscViewerGetSubViewer_Binary in src/sys/classes/viewer/impls/binary/binv.c
PetscViewerGetSubViewer_Draw in src/sys/classes/viewer/impls/draw/drawv.c
PetscViewerGetSubViewer_String in src/sys/classes/viewer/impls/string/stringv.c
Index of all Viewer routines
Table of Contents for all manual pages
Index of all manual pages