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
