MatGetLocalSize() and MatDenseGetLocalMatrix()

[Yujie]

I am sorry, Matthew. I can't understand what you said. You mean it is not
bug? However, practically, the dimension of local matrix in proc1 is 56*108?
if it is, how to obtain its accurate dimension? thanks a lot.

Regards,

Yujie

On Tue, Jan 6, 2009 at 11:45 AM, Matthew Knepley <knepley at gmail.com> wrote:

> On Tue, Jan 6, 2009 at 1:43 PM, Yujie <recrusader at gmail.com> wrote:
>
>> Dear Matthew:
>>
>> Two processors are used. The matrix dimension is 105*108;
>>
>> MatGetOwnershipRange()
>>
>> proc1: 0->56
>>
>> proc2: 56->105
>>
>> Mat->camp.rstart; Mat->cmap.rend
>>
>> proc1: 0->54
>>
>> proc2: 54->108
>>
>> MatGetLocalSize()
>>
>> proc1: row 56 col 54
>>
>> porc2: row 49 col 54
>>
>> MatDenseGetLocalMatrix()
>>
>> proc1: 56*108
>>
>> proc2: 49*108
>>
>
> Since PETSc matrices are all stored row-wise, even if columns are assigned
> to one process
> for the other, the storage is divided by row. This GetLocalMatrix() returns
> all the rows
> associated with a given process.
>
>    Matt
>
>
>> thanks.
>>
>> Yujie
>>
>> On Tue, Jan 6, 2009 at 11:33 AM, Matthew Knepley <knepley at gmail.com>wrote:
>>
>>> On Tue, Jan 6, 2009 at 11:52 AM, Yujie <recrusader at gmail.com> wrote:
>>>
>>>> Dear PETSc developers:
>>>>
>>>> I am trying to use MatGetArray() and MatSetValues() to combine several
>>>> MPIDense matrices into one matrix. At the beginning, I use
>>>>
>>>> MatGetOwnershipRange() and Mat->camp.rstart; Mat->cmap.rend (2.3.3-p8
>>>> version) to get the start, end row and column. I can calculate the local
>>>> rows and columns.
>>>>
>>>> I also use MatGetLocalSize() to confirm the accuracy. However, I always
>>>> find some data loses in the combined matrix.
>>>>
>>>> And then, I try to use MatDenseGetLocalMatrix() to get the lcoal matrix
>>>> and output it. I find column information by MatGetLocalSize() is not
>>>> consistent with by MatDenseGetLocalMatrix(), is it bug? could you give me
>>>> some advice? thanks a lot.
>>>>
>>> What information?
>>>
>>>   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
>
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