[petsc-users] about MatTranspose

[Likun Tan]

Thank you very much. So i should create the transpose matrix as MPIDense
and partition it corresponding? That is, if the matrix is partitioned into
3 parts by row, then the transpose matrix will be partitioned into 3 parts
by column?

I have two more questions:
1. I define a DA with PETSC_COMM_SELF, where is the array stored? Could i
use this array in every process?

2. I vaguely remember that matrix can only be partitioned by row, is that
true?

best,
Likun


On Tue, August 30, 2011 10:07 pm, Matthew Knepley wrote:
> On Wed, Aug 31, 2011 at 12:48 AM, Likun Tan <likunt at andrew.cmu.edu>
> wrote:
>
>
>>
>> I have MPIDense matrix, if i want to get the tranpose of the matrix,
>> what should i do? Or i should use MPISparse instead?
>
>
> If it is rectangular, create the transpose matrix first, then call
> MatTranspose.
>
>
> Matt
>
>
>
>> On Tue, August 30, 2011 7:08 pm, Matthew Knepley wrote:
>>
>>> On Tue, Aug 30, 2011 at 10:59 PM, Likun Tan <likunt at andrew.cmu.edu>
>>> wrote:
>>>
>>>
>>>
>>>>
>>>> Dear all,
>>>>
>>>>
>>>>
>>>> Can MatTranspose be used on non-squra matrix? I have a matrix with
>>>> size 200*27, and i want to get the tranpose of it.
>>>>
>>>>
>>>>
>>>
>>> I assume you are talking about dense matrices. If so, yes.
>>>
>>>
>>>
>>>
>>>> Second question is, if the 200*27 is partitioned by row, how is the
>>>>  tranpose stored in each processor? Is it stored by column?
>>>>
>>>
>>> For MPIDENSE, you cannot in-place transpose unless it is square.
>>> Otherwise,
>>> you provide the transpose matrix, so you determine the layout.
>>>
>>> Matt
>>>
>>>
>>>
>>>
>>>> Thanks,
>>>> Likun
>>>>
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> 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
>
>