Problems passing PyTrilinos objects to DOLFIN matrix/vector

[Joachim Haga]

With trilinos 10.8.3 and latest lp:dolfin, I get errors like the following when trying to create dolfin vectors/matrices:

  File "/home/jobh/src/cbc.block/block/algebraic/trilinos/Epetra.py", line 192, in create_vec
    return dolfin.EpetraVector(m) ### m is a PyTrilinos.Epetra.BlockMap
  File "/home/jobh/src/FEniCS/lib/python2.7/site-packages/dolfin/cpp.py", line 4466, in __init__
    _cpp.EpetraVector_swiginit(self,_cpp.new_EpetraVector(*args))
TypeError: expected positive 'int' for argument 1

  File "/home/jobh/src/cbc.block/block/algebraic/trilinos/Epetra.py", line 299, in create_identity
    matrix = dolfin.EpetraMatrix(graph) ### graph is a PyTrilinos.Epetra.CrsGraph
  File "/home/jobh/src/FEniCS/lib/python2.7/site-packages/dolfin/cpp.py", line 4352, in __init__
    _cpp.EpetraMatrix_swiginit(self,_cpp.new_EpetraMatrix(*args))
TypeError: in method 'new_EpetraMatrix', argument 1 of type 'Epetra_CrsGraph const &'

[Garth Wells (garth-wells)]

On 1 Nov 2011, at 07:32, Joachim Haga <email address hidden> wrote:

> Public bug reported:
>
> With trilinos 10.8.3 and latest lp:dolfin, I get errors like the
> following when trying to create dolfin vectors/matrices:
>
> File "/home/jobh/src/cbc.block/block/algebraic/trilinos/Epetra.py", line 192, in create_vec
> return dolfin.EpetraVector(m) ### m is a PyTrilinos.Epetra.BlockMap
> File "/home/jobh/src/FEniCS/lib/python2.7/site-packages/dolfin/cpp.py", line 4466, in __init__
> _cpp.EpetraVector_swiginit(self,_cpp.new_EpetraVector(*args))
> TypeError: expected positive 'int' for argument 1
>
> File "/home/jobh/src/cbc.block/block/algebraic/trilinos/Epetra.py", line 299, in create_identity
> matrix = dolfin.EpetraMatrix(graph) ### graph is a PyTrilinos.Epetra.CrsGraph
> File "/home/jobh/src/FEniCS/lib/python2.7/site-packages/dolfin/cpp.py", line 4352, in __init__
> _cpp.EpetraMatrix_swiginit(self,_cpp.new_EpetraMatrix(*args))
> TypeError: in method 'new_EpetraMatrix', argument 1 of type 'Epetra_CrsGraph const &'
>

Trilinos nows uses its own shared pointers in its interface. Johan sorted this out for vectors and matrices. Take a look at what he added in the SWIG code. It's probably a case of extending this to more Epetra objects.

Garth

> ** Affects: dolfin
> Importance: Undecided
> Status: New
>
> --
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> https://bugs.launchpad.net/bugs/884617
>
> Title:
> Problems passing PyTrilinos objects to DOLFIN matrix/vector
>
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[Johan Hake (johan-hake)]

We can choose two fixes:

  1) we introduce an overloaded function taking a Teuchos::RCP<EpetraWhatEver> for Dolfin compiled with Trilinos 10.8.3 or more
  2) we introduce a typemap taking either a EpetraWhatEver or a Teuchos::RCP<EpetraWhatEver>

The latter is doable but more complex, as Joachim probably can confirm, but less intrusive for the interface.

[Ole Elvetun (oelvetun)]

Hi,

I have a problem such as described in this post. I have a CrsMatrix (PyTrilinos object), and I would like to pass
this to a dolfin.cpp.matrix, like this naive example:

...
A = assemble(a)
B = down_cast(A).mat()

C = EpetraMatrix(B) #This is what I want to do!

Unfortunately, this last call gives me the same error message as above. I did some different approaches, and to do:

C = EpetraMatrix(B.Graph()) works in the sense that I do not get an error message, but then C does not hold the values
of the sparse matrix, only the structure. I could now run a loop to enter all the values, but this is slow.

Hence, is there some code that might produce what I need quickly?

[Johan Hake (johan-hake)]

On 02/21/2012 02:59 PM, Ole Elvetun wrote:
> Hi,
>
> I have a problem such as described in this post. I have a CrsMatrix (PyTrilinos object), and I would like to pass
> this to a dolfin.cpp.matrix, like this naive example:
>
> ...
> A = assemble(a)
> B = down_cast(A).mat()
>
> C = EpetraMatrix(B) #This is what I want to do!
>
> Unfortunately, this last call gives me the same error message as above.
> I did some different approaches, and to do:
>
> C = EpetraMatrix(B.Graph()) works in the sense that I do not get an error message, but then C does not hold the values
> of the sparse matrix, only the structure. I could now run a loop to enter all the values, but this is slow.
>
> Hence, is there some code that might produce what I need quickly?

We need to add a typemap for this to be possible. It should be pretty
straight forward. We might not get the benefit of automatic shared_ptr
handling as we use different shared_ptr in dolfin and PyTrilinos.

I can have a look at this later today.

Johan

[Joachim Haga (jobh)]

On 21 February 2012 15:15, Johan Hake <email address hidden> wrote:

> On 02/21/2012 02:59 PM, Ole Elvetun wrote:
> >
> > I have a problem such as described in this post. I have a CrsMatrix
> (PyTrilinos object), and I would like to pass
> > this to a dolfin.cpp.matrix, like this naive example:
>
> We need to add a typemap for this to be possible. It should be pretty
> straight forward. We might not get the benefit of automatic shared_ptr
> handling as we use different shared_ptr in dolfin and PyTrilinos.
>

If the C++ interface is there, I think it should be as simple as adding

%RCP_to_const_ref_typemap(Epetra_CrsMatrix);

along with the other RCP_to_... in la/pre.i. Or maybe it has to be a
FECrsMatrix?

-j.

[Johan Hake (johan-hake)]

On 02/21/2012 04:29 PM, Joachim Haga wrote:
> On 21 February 2012 15:15, Johan Hake<email address hidden> wrote:
>
>> On 02/21/2012 02:59 PM, Ole Elvetun wrote:
>>>
>>> I have a problem such as described in this post. I have a CrsMatrix
>> (PyTrilinos object), and I would like to pass
>>> this to a dolfin.cpp.matrix, like this naive example:
>>
>> We need to add a typemap for this to be possible. It should be pretty
>> straight forward. We might not get the benefit of automatic shared_ptr
>> handling as we use different shared_ptr in dolfin and PyTrilinos.
>>
>
> If the C++ interface is there, I think it should be as simple as adding
>
> %RCP_to_const_ref_typemap(Epetra_CrsMatrix);
>
> along with the other RCP_to_... in la/pre.i. Or maybe it has to be a
> FECrsMatrix?

It have to be a shared_ptr version of that type. Working on it... Not
that straight forward actually.

Johan

> -j.
>