Comparing matrices between 2 different codes and viewing of matrix

[Ben Tay]

Hi Barry,

Got it working. Thanks alot!

Barry Smith wrote:
>
>    You use EITHER PetscViewerCreate() and PetscViewerSetType() and 
> PetscViewerFileSetName() OR PetscViewerASCIIOpen()
> so use
>
>
>> call PetscViewerASCIIOpen(MPI_COMM_WORLD, "matrix.txt",viewer,ierr)
>>> call MatView(A_mat_uv,viewer,ierr)
>> call PetscViewerDestroy(viewer,ierr)
>
>
>
> On May 27, 2008, at 5:57 AM, Ben Tay wrote:
>
>> Hi Barry,
>>
>> Thanks for pointing out. However, I only got a 0 byte file after 
>> adding the include statement.
>>
>> I am programming in parallel and my matrix is created using 
>> MatCreateMPIAIJ. Did I missed out some commands?
>>
>> PetscViewer viewer
>>
>>
>> ...
>>
>> call  PetscViewerCreate(MPI_COMM_WORLD,viewer,ierr)
>>
>> call MatView(A_mat_uv,viewer,ierr)
>>
>> call PetscViewerASCIIOpen(MPI_COMM_WORLD, "matrix.txt",viewer,ierr)
>>
>> call PetscViewerDestroy(viewer,ierr)
>>
>> Thank you very much.
>>
>> Regards.
>>
>>
>> Barry Smith wrote:
>>>
>>>   Likely you forgot to #include "finclude/petscviewer.h" in the 
>>> Fortran subroutine that
>>> is doing this stuff.
>>>
>>>
>>> On May 25, 2008, at 5:43 AM, Ben Tay wrote:
>>>
>>>> Hi,
>>>>
>>>> I have an old serial code and a newer parallel code. The new 
>>>> parallel code is converted from the old serial code. However, due 
>>>> to numerous changes, the answers from the new code now differs from 
>>>> the old one after the 1st step. What is the best way to compare the 
>>>> matrices from the 2 different code?
>>>>
>>>> I guess the most direct mtd is to use MatView to store the matrix 
>>>> in a ACSII file and spot the difference between the 2 files. 
>>>> However, I can't seem to get it right. What I did is:
>>>>
>>>> PetscViewer viewer
>>>>
>>>> call  PetscViewerCreate(PETSC_COMM_SELF,viewer,ierr)
>>>>
>>>> call MatView(A_mat_uv,viewer,ierr)
>>>>
>>>> call PetscViewerDestroy(viewer,ierr)
>>>>
>>>> call PetscViewerASCIIOpen(PETSC_COMM_SELF, "matrix.txt",viewer,ierr)
>>>>
>>>> However, I get the error that "PetscViewer viewer" has syntax 
>>>> error. Hope you can help me out.
>>>>
>>>> Thank you very much.
>>>>
>>>> Regards
>>>>
>>>>
>>>
>>>
>>
>>
>
>