How to get information about the off-diagonal submatrix

[Thomas Witkowski]

Satish Balay wrote:
> Its also possible that some values are set on other procs and
> commuincated..
>   
That's the reason, I've forgotten to check it. Thanks for the hint! Is 
there any way to get information from petsc to check how many matrix 
entries had to be communicated during assembling?

Thomas



> Note: I should have mentioned earlier: mpiaij->B is an internal
> datastructure - so the column indices don't directly correspond to the
> original matrix. [there is a cmap in there that stores this map]
>
> Satish
>
> On Mon, 10 Aug 2009, Thomas Witkowski wrote:
>
>   
>> Thanks, that works fine! In my test case (yes, just for debugging!) I've
>> expected to have an empty off-diagonal matrix. But the matrix is not empty.
>> But how is it possible, when all entries, which are inserted to the matrix via
>> MatSetValues, have indices for row and col within the ownership range of the
>> processors matrix?
>>
>> Thomas
>>
>> Satish Balay wrote:
>>     
>>> alternatively - just access the private datastructe and print..
>>>
>>> #include "../src/mat/impls/aij/mpi/mpiaij.h"
>>> Mat_MPIAIJ     *mpiaij = (Mat_MPIAIJ*)mat->data;
>>> MatView(mpiaij->B,...);
>>>
>>>
>>> Satish
>>>
>>>
>>> On Mon, 10 Aug 2009, Matthew Knepley wrote:
>>>
>>>   
>>>       
>>>> If this is just for debugging, the easiest way I think is to call
>>>> MatGetSubmatrix() with
>>>> a column IS that omits the local columns.
>>>>
>>>>   Matt
>>>>
>>>> On Mon, Aug 10, 2009 at 8:28 AM, Thomas Witkowski <
>>>> thomas.witkowski at tu-dresden.de> wrote:
>>>>
>>>>     
>>>>         
>>>>> Hi,
>>>>>
>>>>> how is it possible to print just the off-diagonal submatrix of one
>>>>> process
>>>>> of a parallel mpiaij matrix?
>>>>>
>>>>> Thomas
>>>>>
>>>>>       
>>>>>           
>>>>     
>>>>         
>>>
>>>   
>>>       
>>     
>
>
>
>