PetscViewerASCIIOpen#

Opens an ASCII file for writing as a PETSCVIEWERASCII PetscViewer.

Synopsis#

#include "petscviewer.h"   
PetscErrorCode PetscViewerASCIIOpen(MPI_Comm comm, const char name[], PetscViewer *viewer)

Collective

Input Parameters#

comm - the communicator
name - the file name

Output Parameter#

viewer - the PetscViewer to use with the specified file

Notes#

This routine only opens files for writing. To open a ASCII file as a PetscViewer for reading use the sequence

   PetscViewerCreate(comm,&viewer);
   PetscViewerSetType(viewer,PETSCVIEWERASCII);
   PetscViewerFileSetMode(viewer,FILE_MODE_READ);
   PetscViewerFileSetName(viewer,name);

This PetscViewer can be destroyed with PetscViewerDestroy().

The MPI communicator used here must match that used by the object viewed. For example if the Mat was created with a PETSC_COMM_WORLD, then viewer must be created with PETSC_COMM_WORLD

As shown below, PetscViewerASCIIOpen() is useful in conjunction with MatView() and VecView()

     PetscViewerASCIIOpen(PETSC_COMM_WORLD,"mat.output",&viewer);
     MatView(matrix,viewer);

Developer Note#

When called with NULL, stdout, or stderr this does not return the same communicator as PetscViewerASCIIGetStdout() or PetscViewerASCIIGetStderr() but that is ok.