[Trilinos-Users] Questions about InsertGlobalValues

[M. Scot Breitenfeld]

  I have a few questions about the use of InsertGlobalValues for 
Epetra_FECrsMatrix class matrix, which is for my K matrix. Currently I 
form one row and then use the InsertGlobalValues routine to add it to K 
(I'm forming the row array in a Fortran program). Is it better (faster) 
to form more rows and then send that to InsertGlobalValues, or does it 
not matter.

Also, I'm getting an error in Epetra_CrsGraph.cpp:

Epetra_CrsGraph::InsertIndices(int Row,
                    int NumIndices,
                    int* UserIndices)

by  failing
     if(current_numAllocIndices == 0) {
     int * temp = new int[NumIndices];
     CrsGraphData_->Indices_[Row] = temp;
       }
       else {
     ierr = 3; // Out of room.  Must allocate more space, copy and 
delete...

and getting ierr = 3. Is there something I'm doing wrong to get this error?

I'm trying to track down a memory problem where it is taking more memory 
to store K then it would to just storing the full matrix with all the 
zero coefficients. I've tracked it down to the InsertGlobalValues but I 
have not found the source of the problem. This happens regardless if I 
run it in serial or parallel. It also takes an extremely long time to 
assemble the matrix (it takes longer then solving the system of 
equations), but I suspect it is related to the memory problems.