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 443f08860eSBarry Smith .seealso: PetscViewerSocketOpen(), PetscViewerASCIIOpen(), PetscViewerDrawOpen(), PetscViewerRestoreSubViewer() 455c6c1daeSBarry Smith @*/ 463f08860eSBarry Smith PetscErrorCode PetscViewerGetSubViewer(PetscViewer viewer,MPI_Comm comm,PetscViewer *outviewer) 475c6c1daeSBarry Smith { 485c6c1daeSBarry Smith PetscFunctionBegin; 495c6c1daeSBarry Smith PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1); 50064a246eSJacob Faibussowitsch PetscValidPointer(outviewer,3); 519530cbd7SBarry Smith if (viewer->ops->getsubviewer) { 52*9566063dSJacob Faibussowitsch PetscCall((*viewer->ops->getsubviewer)(viewer,comm,outviewer)); 5398921bdaSJacob Faibussowitsch } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot get SubViewer PetscViewer for type %s",((PetscObject)viewer)->type_name); 545c6c1daeSBarry Smith PetscFunctionReturn(0); 555c6c1daeSBarry Smith } 565c6c1daeSBarry Smith 57b3fa1ec5SBarry Smith /*@C 583f08860eSBarry Smith PetscViewerRestoreSubViewer - Restores a new PetscViewer obtained with PetscViewerGetSubViewer(). 595c6c1daeSBarry Smith 605c6c1daeSBarry Smith Collective on PetscViewer 615c6c1daeSBarry Smith 625c6c1daeSBarry Smith Input Parameters: 633f08860eSBarry Smith + viewer - the PetscViewer that was reproduced 645c6c1daeSBarry Smith - outviewer - new PetscViewer 655c6c1daeSBarry Smith 665c6c1daeSBarry Smith Level: advanced 675c6c1daeSBarry Smith 6895452b02SPatrick Sanan Notes: 6995452b02SPatrick Sanan Call PetscViewerGetSubViewer() to get this PetscViewer, NOT PetscViewerCreate() 705c6c1daeSBarry Smith 713f08860eSBarry Smith .seealso: PetscViewerSocketOpen(), PetscViewerASCIIOpen(), PetscViewerDrawOpen(), PetscViewerGetSubViewer() 725c6c1daeSBarry Smith @*/ 733f08860eSBarry Smith PetscErrorCode PetscViewerRestoreSubViewer(PetscViewer viewer,MPI_Comm comm,PetscViewer *outviewer) 745c6c1daeSBarry Smith { 755c6c1daeSBarry Smith PetscFunctionBegin; 765c6c1daeSBarry Smith PetscValidHeaderSpecific(viewer,PETSC_VIEWER_CLASSID,1); 77ffc4695bSBarry Smith 789530cbd7SBarry Smith if (viewer->ops->restoresubviewer) { 79*9566063dSJacob Faibussowitsch PetscCall((*viewer->ops->restoresubviewer)(viewer,comm,outviewer)); 8098921bdaSJacob Faibussowitsch } else SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP,"Cannot restore SubViewer PetscViewer for type %s",((PetscObject)viewer)->type_name); 815c6c1daeSBarry Smith PetscFunctionReturn(0); 825c6c1daeSBarry Smith } 83