15c6c1daeSBarry Smith 2af0996ceSBarry Smith #include <petsc/private/viewerimpl.h> /*I "petscviewer.h" I*/ 35c6c1daeSBarry Smith 4b3fa1ec5SBarry Smith /*@C 53f08860eSBarry Smith PetscViewerGetSubViewer - Creates a new PetscViewer (same type as the old) 63f08860eSBarry Smith that lives on a subcommunicator 75c6c1daeSBarry Smith 85c6c1daeSBarry Smith Collective on PetscViewer 95c6c1daeSBarry Smith 105c6c1daeSBarry Smith Input Parameter: 113f08860eSBarry Smith . viewer - the PetscViewer to be reproduced 125c6c1daeSBarry Smith 135c6c1daeSBarry Smith Output Parameter: 145c6c1daeSBarry Smith . outviewer - new PetscViewer 155c6c1daeSBarry Smith 165c6c1daeSBarry Smith Level: advanced 175c6c1daeSBarry Smith 1895452b02SPatrick Sanan Notes: 19a62913d3SBarry Smith The output of the subviewers is synchronized against the original viewer. For example, if a 20a62913d3SBarry Smith viewer on two MPI ranks is decomposed into two subviewers, the output from the first viewer is 21a62913d3SBarry Smith all printed before the output from the second viewer. You must call PetscViewerFlush() after 22a62913d3SBarry Smith the call to PetscViewerRestoreSubViewer(). 23a62913d3SBarry Smith 24a62913d3SBarry Smith Call PetscViewerRestoreSubViewer() to destroy this PetscViewer, NOT PetscViewerDestroy() 255c6c1daeSBarry Smith 265c6c1daeSBarry Smith This is most commonly used to view a sequential object that is part of a 275c6c1daeSBarry Smith parallel object. For example block Jacobi PC view could use this to obtain a 285c6c1daeSBarry Smith PetscViewer that is used with the sequential KSP on one block of the preconditioner. 295c6c1daeSBarry Smith 30e5afcf28SBarry Smith Between the calls to PetscViewerGetSubViewer() and PetscViewerRestoreSubViewer() the original 31e5afcf28SBarry Smith viewer should not be used 32e5afcf28SBarry Smith 33e5afcf28SBarry Smith PETSCVIEWERDRAW and PETSCVIEWERBINARY only support returning a singleton viewer on rank 0, 34e5afcf28SBarry Smith all other ranks will return a NULL viewer 35e5afcf28SBarry Smith 36e5afcf28SBarry Smith Developer Notes: 37e5afcf28SBarry Smith There is currently incomplete error checking that the user does not use the original viewer between the 38e5afcf28SBarry Smith the calls to PetscViewerGetSubViewer() and PetscViewerRestoreSubViewer(). If the user does there 39e5afcf28SBarry Smith could be errors in the viewing that go undetected or crash the code. 40e5afcf28SBarry Smith 41a62913d3SBarry Smith It would be nice if the call to PetscViewerFlush() was not required and was handled by 42a62913d3SBarry Smith PetscViewerRestoreSubViewer() 43a62913d3SBarry Smith 44db781477SPatrick Sanan .seealso: `PetscViewerSocketOpen()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewerRestoreSubViewer()` 455c6c1daeSBarry Smith @*/ 46*9371c9d4SSatish Balay PetscErrorCode PetscViewerGetSubViewer(PetscViewer viewer, MPI_Comm comm, PetscViewer *outviewer) { 475c6c1daeSBarry Smith PetscFunctionBegin; 485c6c1daeSBarry Smith PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 1); 49064a246eSJacob Faibussowitsch PetscValidPointer(outviewer, 3); 50dbbe0bcdSBarry Smith PetscUseTypeMethod(viewer, getsubviewer, comm, outviewer); 515c6c1daeSBarry Smith PetscFunctionReturn(0); 525c6c1daeSBarry Smith } 535c6c1daeSBarry Smith 54b3fa1ec5SBarry Smith /*@C 553f08860eSBarry Smith PetscViewerRestoreSubViewer - Restores a new PetscViewer obtained with PetscViewerGetSubViewer(). 565c6c1daeSBarry Smith 575c6c1daeSBarry Smith Collective on PetscViewer 585c6c1daeSBarry Smith 595c6c1daeSBarry Smith Input Parameters: 603f08860eSBarry Smith + viewer - the PetscViewer that was reproduced 615c6c1daeSBarry Smith - outviewer - new PetscViewer 625c6c1daeSBarry Smith 635c6c1daeSBarry Smith Level: advanced 645c6c1daeSBarry Smith 6595452b02SPatrick Sanan Notes: 6695452b02SPatrick Sanan Call PetscViewerGetSubViewer() to get this PetscViewer, NOT PetscViewerCreate() 675c6c1daeSBarry Smith 68db781477SPatrick Sanan .seealso: `PetscViewerSocketOpen()`, `PetscViewerASCIIOpen()`, `PetscViewerDrawOpen()`, `PetscViewerGetSubViewer()` 695c6c1daeSBarry Smith @*/ 70*9371c9d4SSatish Balay PetscErrorCode PetscViewerRestoreSubViewer(PetscViewer viewer, MPI_Comm comm, PetscViewer *outviewer) { 715c6c1daeSBarry Smith PetscFunctionBegin; 725c6c1daeSBarry Smith PetscValidHeaderSpecific(viewer, PETSC_VIEWER_CLASSID, 1); 73ffc4695bSBarry Smith 74dbbe0bcdSBarry Smith PetscUseTypeMethod(viewer, restoresubviewer, comm, outviewer); 755c6c1daeSBarry Smith PetscFunctionReturn(0); 765c6c1daeSBarry Smith } 77