[Trilinos-Users] Trouble with Teuchos Epetra_CrsMatrix

[Hoemmen, Mark]

On Mar 6, 2013, at 12:00 PM, <trilinos-users-request at software.sandia.gov>
 wrote:
> Message: 1
> Date: Wed, 6 Mar 2013 20:42:01 +0900
> From: "SungHwan Choi" <sunghwanchoi91 at gmail.com>
> Subject: [Trilinos-Users] Trouble with Teuchos Epetra_CrsMatrix
> To: trilinos-users at software.sandia.gov
> Message-ID:
> 	<CAF=G9Hw=oSxGtab3KBh_Jka6Nj3yK6YSuaj9Xk9rPNGZGhhZyQ at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
> 
> Dear all,
> 
> I'm confusing how to use teuchos epetra_crsmatrix in the following case.
> (using c++)
> 
> ------------------------------------------------------------------------------------------------------
> class A{
>  Teuchos::RCP<Epetra_CrsMatrix> matrix;
>  A::A(){
>    matrix=Teuchos::rcp(new Epetra_CrsMatrix(blah, blah, ...));
>    B* b=new B();
>    B->compute(matrix);
>    xxxxx
>    xxxxx
>  }
> }
> 
> class B{
>  void B::compute(Teuchos::RCP<Epetra_CrsMatrix> matrix){
>    matrix->InsertGlobalValues(blah, blah, ...);
>  }
> }
> ------------------------------------------------------------------------------------------------------
> 
> I declare "Teuchos::RCP<Epetra_CrsMatrix> matrix" in class A, and insert
> values of matrix using the function in class B.
> Also, xxxxx in class A, I want to calculate something with "matrix" (For
> example, calculate another value with "matrix").
> The above description is right or wrong?
> Thank you.

I don't understand what you mean by this question.  Are you asking whether the code is syntactically correct?  It looks syntactically correct to me, but I don't think you need so many pointers.  For example:

A::A () {
  matrix = Teuchos::rcp (new Epetra_CrsMatrix (…));
  B b;
  b.compute (matrix);
}

You don't even need an RCP if the class A never shares the matrix with anything else, though using an RCP means that you don't have to worry about deallocating the matrix in the destructor of class A.

mfh