MatGetArrayF90 returns 2d array

[Barry Smith]

   #include "src/mat/impls/aij/seq/aij.h"     :-)


On Jul 2, 2009, at 2:59 PM, Lisandro Dalcin wrote:

> On Thu, Jul 2, 2009 at 1:47 PM, Barry Smith<bsmith at mcs.anl.gov> wrote:
>>
>>  MatGetArray() returns access to the nonzero values of the matrix  
>> in a
>> format that depends on the underlying class. It is a perfectly  
>> reasonable
>> method and has been there for decades just fine.
>>
>
> BTW, Matt commented about PETSc providing support for obtaining the
> AIJ structure... I know how to get the "IJ" part, MatGetArray() let me
> get the "A" part, but ... Where is the call that let one to get the
> whole data, indices and values?
>
>
>>  Barry
>>
>> On Jul 1, 2009, at 5:54 PM, Matthew Knepley wrote:
>>
>>> On Thu, Jul 2, 2009 at 2:36 AM, Barry Smith <bsmith at mcs.anl.gov>  
>>> wrote:
>>>
>>> Satish,
>>>
>>>  Could you please convert these (both the stub code and the F90  
>>> interface)
>>> to use a 1d array? In both 3.0.0 and petsc-dev.
>>>
>>> I am still against this, since it seems much nicer to get a 2D array
>>> for the dense matrix, which is the ONLY matrix for which GetArray()
>>> makes any sense I think.
>>>
>>>  Matt
>>>
>>>
>>>  Thanks
>>>
>>>  Barry
>>>
>>> On Jun 30, 2009, at 6:37 PM, Jed Brown wrote:
>>>
>>> Matthew Knepley wrote:
>>> I thought the idea was that MatGetArray() never applies to a sparse
>>> matrix.  No other sparse format supports this, does it?
>>>
>>> That's not true at all, but the result is implementation- 
>>> dependent.  For
>>> example, the array for AIJ is different from the array for BAIJ.   
>>> For
>>> this reason, you shouldn't be calling MatGetArray unless you know  
>>> the
>>> matrix type, but of course the F90 interface should agree with the C
>>> interface.
>>>
>>> Jed
>>>
>>>
>>>
>>>
>>>
>>> --
>>> 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
>>
>>
>
>
>
> -- 
> Lisandro Dalcín
> ---------------
> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
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