[Trilinos-Users] Received elements must be stored after all x local elements

[Daniele Bettella]

Ok, this is the code that faults

    int NumGlobalElements = A.nrows();

    // creates map
    Epetra_Map gmap(NumGlobalElements, 0, Comm);
    int NumMyElements = gmap.NumMyElements();
    int * MyGlobalElements = gmap.MyGlobalElements();
    Epetra_CrsMatrix Atr(Copy, gmap, A.ncols());

    //adjusting the iterators for each process
    typename gmm::linalg_traits<MAT>::const_row_iterator itm =
mat_row_const_begin(A);
    for(int i=0; i<MyGlobalElements[0]; i++) itm++;
    typename gmm::linalg_traits<MAT>::const_row_iterator itme = itm;
    for(int i=0; i<NumMyElements; i++) itme++;

    //we access the row of the matrix
    typedef typename gmm::linalg_traits<MAT>::const_sub_row_type rowtype;
    rowtype row;
    int nnzRow;
    double* Values;
    int* Indices;
    int icount=0;

    //now we copy the matrix by row
    while(itm != itme){
      row = gmm::linalg_traits<MAT>::row(itm);
      nnzRow = gmm::nnz(row);
      Values = new double[nnzRow];
      Indices = new int[nnzRow];
      typename gmm::linalg_traits<rowtype>::const_iterator itv =
vect_const_begin(row);
      typename gmm::linalg_traits<rowtype>::const_iterator itve =
vect_const_end(row);
      int j = 0;
      while(itv != itve){
	Values[j] = *itv;
	Indices[j] = itv.index();
	++itv;
	++j;
      }
      // and we insert values and indices in epetra matrix
      Atr.InsertGlobalValues(MyGlobalElements[icount], nnzRow, Values, Indices);
      ++itm;
      ++icount;
    }
    Atr.FillComplete();


This is the code that copies the matrix; as said before, the error
comes out when initializing an aztecoo object:
    Epetra_LinearProblem problem(&Atr, &Xtr, &Btr);
    AztecOO solver(problem);

where Xtr and Btr can be any vector.
Again, the error doesn't appear if the matrix has a main diagonal of nonzeros

This is what I could come out with, hope it helps!

Daniele


On Wed, Sep 10, 2008 at 9:20 PM, Heroux, Michael A <maherou at sandia.gov> wrote:
> Daniele,
>
> Do you have a simple example program that you could send?
>
> Mike
>
>
> On 9/10/08 2:23 AM, "Daniele Bettella" <sunriis at gmail.com> wrote:
>
> Hi, I'm having a problem with AztecOO:
> when initializing the aztecoo object the error written in the subject pops
> out.
> I'm translating a sparse matrix from another format by hand; let's say I
> have the following nonzeros in a 3x3 matrix:
> A(0,0), A(0,2), A(1,0), A(2,1), A(2,2)
>
> what I do is create a map with the number of rows (3)
>
> Epetra_Map gmap(nrows, 0, comm)
>
> then I do
>
> Epetra_CrsMatrix newA(Copy, gmap, ncols)
>
> I then insert the elements by hand, cycling through the rows. Using MPI and
> more then one process I divide the matrix to be translated in partitions of
> rows, assigned to each process as per map definition.
>
> With the example matrix written above I get the error
> AZ_extract_comm_info: Received elements must be stored after all 2 local
> elements
>
>  but if I add an element in position A(1,1), obtaining a matrix with a main
> diagonal of nonzeros, the error disappears.
>
> Any clue would be greatly appreciated, thanks in advance.
>
> Daniele
>
>
>