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

[Matthew Knepley]

MatView_SeqAIJ_Draw_Zoom() in src/mat/impls/aij/seq/aij.c

To find any function, I would use the debugger.

  Matt

On Jan 23, 2008 8:38 PM, Yujie <recrusader at gmail.com> wrote:
> To generate the sparsity picture, could you tell me how to find the code
> used by "-mat_view_draw"? I have searched the whole PETSc package. However,
> it is difficult to find it. Thanks a lot.
>
> Regards,
> Yujie
>
> On 1/23/08, Matthew Knepley <knepley at gmail.com> wrote:
> > On Jan 23, 2008 2:18 PM, Yujie <recrusader at gmail.com> wrote:
> > > Thank you for your further explanation. I just want to use this data in
> > > other packages. I think that ASCII file is likely better. Because I
> don't
> > > know the format of the binary file? how to find it?
> >
> > Look at MatView_SeqAIJ_Binary() in src/mat/impls/aij/seq/aij.c. The
> > format is pretty simple.
> >
> > > In addition, do you have any better methods to save the sparsity
> structure
> > > picture of the matrix? Now, I use "-mat_view_draw" to do this. However,
> the
> > > speed is very slow and the picture is small. I want to get a big picture
> and
> > > directly save it to the disk?
> > >  could you give me some advice? thanks a lot.
> >
> > We do not have a better way to make the sparsity picture. I assume you
> could
> > write something that decides how many pixels to use, calculates an average
> > occupancy per pixel, and writes a BMP or something.
> >
> >   Matt
> >
> > > Regards,
> > > Yujie
> > >
> > > On 1/23/08, Matthew Knepley <knepley at gmail.com > wrote:
> > > > On Jan 22, 2008 11:01 PM, Yujie < recrusader at gmail.com> wrote:
> > > > > Dear Matt:
> > > > >
> > > > > thank you for your reply. Do you have any method to generate an
> ascii
> > > file
> > > > > of the huge sparse matrix? thanks
> > > >
> > > > I think you miss my point. The PETSc function is not a bad way to
> generate
> > > > ASCII matrices. ASCII matrices make "no sense" for large operators.
> > > >
> > > >    Matt
> > > >
> > > > > Regards,
> > > > > Yujie
> > > > >
> > > > >
> > > > >
> > > > > On 1/23/08, Matthew Knepley <knepley at gmail.com > wrote:
> > > > > > 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
> > > > > >
> > > > > >   PetscViewerCreate()
> > > > > >   PetscViewerSetType()
> > > > > >   PetscViewerFileSetMode()
> > > > > >   PetscViewerFileSetName()
> > > > > >
> > > > > > 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.
> > > > > >
> > > > > >    Matt
> > > > > >
> > > > > > > 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
> > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > --
> > > > 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
> > > >
> > > >
> > >
> > >
> >
> >
> >
> > --
> > 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
> >
> >
>
>



-- 
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