petsc-3.3-p7 2013-05-11

PetscViewerASCIIOpen

Opens an ASCII file as a PetscViewer.

Synopsis

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

Collective on MPI_Comm

Input Parameters

	comm	- the communicator
	name	- the file name

Output Parameter

lab -the PetscViewer to use with the specified file

Notes

This PetscViewer can be destroyed with PetscViewerDestroy().

If a multiprocessor communicator is used (such as PETSC_COMM_WORLD), then only the first processor in the group opens the file. All other processors send their data to the first processor to print.

Each processor can instead write its own independent output by specifying the communicator PETSC_COMM_SELF.

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

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

Examples