Problem with MatMatMultTranspose

[Matthew Knepley]

On Fri, Sep 18, 2009 at 8:48 AM, Hong Zhang <hzhang at mcs.anl.gov> wrote:

>
> Should we create a new matrix type, say hbaij,
> for operations of Hermitian matrices?
>

No, it should be a minor perturbation.

  Matt


> Hong
>
>
> On Fri, 18 Sep 2009, Matthew Knepley wrote:
>
>  On Fri, Sep 18, 2009 at 7:32 AM, Niall Moran <nmoran at thphys.nuim.ie>
>> wrote:
>>
>>  Matthew Knepley wrote:
>>>
>>>  On Thu, Sep 17, 2009 at 12:44 PM, Niall Moran <nmoran at thphys.nuim.ie
>>>> <mailto:
>>>> nmoran at thphys.nuim.ie>> wrote:
>>>>
>>>>   Hi,
>>>>
>>>>   I am just wondering if anything has changed on the status of this
>>>>   feature. Would be great to be able to perform matrix vector
>>>>   multiplications on complex Hermitian matrices by only providing
>>>>   one half of the matrix.
>>>>
>>>>
>>>> It is not curently in the todo list since we have only had one request.
>>>> It
>>>> seems like it would just take being careful about the
>>>> complex case for SBAIJ if you would like the try the implementation. We
>>>> can answer questions.
>>>>
>>>>  Thanks for you rapid response. I would be interested in attempting to
>>>>
>>> implement this for MPIAIJ if it would not be too involved. Would you be
>>> able
>>> to sketch a rough outline of what this would involve? Would I need to
>>> just
>>> modify the MatMult_MPIAIJ function or would I need to modify the creation
>>> of
>>> the scatterers in MatAssemblyBegin_MPIAIJ?
>>>
>>> Could anyone suggest some documentation that describes how the matrix
>>> vector multiplication works in petsc for MPIAIJ typed matrices?
>>>
>>> Does matrix vector multiplication with just the upper half work for real
>>> symmetric matrices?
>>>
>>>
>> 1) Understand the SBAIJ implementation. This is used for real symmetric
>> matrices
>>
>> 2) In the places where the lower triangle is retrieved, add a complex
>> conjugation.
>>
>>  Matt
>>
>>
>>  Regards,
>>>
>>> Niall.
>>>
>>>  --
>> 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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