what's the difference between PetscViewerASCIIOpen() and PetscViewerBinaryOpen()?

Matthew Knepley knepley at gmail.com
Tue Jan 22 21:25:43 CST 2008

On Jan 22, 2008 8:50 PM, Yujie <recrusader at gmail.com> wrote:
> Hi everyone:
> #include "petsc.h"
>  PetscErrorCode PetscViewerASCIIOpen(MPI_Comm comm,const char
> name[],PetscViewer *lab)
> #include "petsc.h"
>  PetscErrorCode PetscViewerBinaryOpen(MPI_Comm comm,const char
> name[],PetscFileMode type,PetscViewer *binv)
> if the difference between them is that one for ASCII output and the other
> for Binary output, why are there different parameters?

It is historical. If you want to be generic, you should use


which can create both.

> The speed to output matrix is very fast when I use  PetscViewerBinaryOpen.
> However, when I use PetscViewerASCIIOpen, I can't get the matrix output. the
> code always is running and it has taken about one day! what's the problem?
> thank you.

ASCII files do not make sense for large matrices. You should use binary files.


> Regards,
> Yujie

What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
-- Norbert Wiener

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