[petsc-users] Problem with Mat.setpreallocationNNZ in petsc4py

[Matthew Knepley]

On Sat, Jul 7, 2012 at 11:02 AM, Xin Zhao <sean.null at gmail.com> wrote:

> yeap...sorry...
> L=DA.createMat()
>
> then
> L.setPreallocationNNZ((3,2))
>

As I said, its already preallocated.

  Matt


> On Sat, Jul 7, 2012 at 6:01 PM, Matthew Knepley <knepley at gmail.com> wrote:
>
>> On Sat, Jul 7, 2012 at 10:58 AM, Xin Zhao <sean.null at gmail.com> wrote:
>>
>>> Dear all,
>>>
>>> I generate a matrix L by
>>> DA =PETSc.DA().create(...some...)
>>> L = DA.create()
>>>
>>
>> Is this createMatrix()? The matrix returned from a DA is already
>> preallocated.
>>
>>    Matt
>>
>>
>>> Then I want to preallocate memory for L
>>> L.setPreallocationNNZ((3,2))
>>> This works when for mpiexec -np 1
>>> but it gives the error message below when mpiexec -np 4
>>>
>>> [3] MatAnyAIJSetPreallocation() line 311 in
>>> petsc4py-1.2/src/include/custom.h
>>> [3] Operation done in wrong order
>>> [3] matrix is already preallocated
>>>
>>> How to solve this?
>>>
>>> Thanks in advance.
>>>
>>> Cheers,
>>> Xin
>>>
>>
>>
>>
>> --
>> 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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