[Trilinos-Users] Aztec00 Question

[John Mitchell]

Hello,

I am having trouble understanding why the following "diagonal" linear 
system will not solve?

The entire system is a 6x6 matrix and is run on two processors.  Each 
processor owns a row of  2 3x3 matrices.  The matrix and RHS vector are 
given below and the Aztec "warning" message is also printed. 
By inspection, the solution for GID=3 should be .001 but that is not 
produced?

In this case I have dirichlet boundary conditions on all points and so 
there are 1's on the diagonal and the rest of the entries are zero.  
Note that the 2nd row has the columns swapped?  I'm hoping thats not an 
issue with the solver or graph?  Of course when I fill these entries 
this is specified and I get no return errors.

Any thoughts/suggestions?
John

local row Id = 0; global rowId = 0; col gIds = 0, 1
    1.000000e+00 0.000000e+00 0.000000e+00     0.000000e+00 0.000000e+00 
0.000000e+00
    0.000000e+00 1.000000e+00 0.000000e+00     0.000000e+00 0.000000e+00 
0.000000e+00
    0.000000e+00 0.000000e+00 1.000000e+00     0.000000e+00 0.000000e+00 
0.000000e+00




local row Id = 0; global rowId = 1; col gIds = 1, 0
    1.000000e+00 0.000000e+00 0.000000e+00     0.000000e+00 0.000000e+00 
0.000000e+00
    0.000000e+00 1.000000e+00 0.000000e+00     0.000000e+00 0.000000e+00 
0.000000e+00
    0.000000e+00 0.000000e+00 1.000000e+00     0.000000e+00 0.000000e+00 
0.000000e+00


Rhs Vector
----------
Epetra::Vector     MyPID           GID               Value 
         0             0                       0
         0             1                       0
         0             2                       0

Epetra::Vector        
         1             3                   0.001
         1             4                       0
         1             5                       0

===============================================================================
AZ_check_input: Setup information on processor 0

    solver:                    0
    convergence flag:            0
    maximum iterations:            500
    reordering:                    1
    preconditioner:                1
    polynomial order:            1
    tolerance:                1.0e-06
    drop:                    0.0e+00

    Number of internal unknowns:        0
    Number of border  unknowns:        3
    Total number of unknowns:        3
    Number of external unknowns:        3
    Number of internal blocks:        0
    Number of border  blocks:        3
    Total number of blocks:            3
    Number of external blocks:        3
    Number of processors:            2
    Node number:                0
    Number of neighbors:            1
    Number of unknowns sent to neighbors:    3
===============================================================================
AZ_check_input: Setup information on processor 0

    solver:                    0
    convergence flag:            0
    maximum iterations:            500
    reordering:                    1
    preconditioner:                1
    polynomial order:            1
    tolerance:                1.0e-06
    drop:                    0.0e+00

    Number of internal unknowns:        0
    Number of border  unknowns:        3
    Total number of unknowns:        3
    Number of external unknowns:        3
    Number of internal blocks:        0
    Number of border  blocks:        3
    Total number of blocks:            3
    Number of external blocks:        3
    Number of processors:            2
    Node number:                0
    Number of neighbors:            1
    Number of unknowns sent to neighbors:    3
===============================================================================

        *******************************************************
        ***** Problem: Epetra::VbrMatrix
        ***** Preconditioned CG solution
        ***** 1 step block Jacobi
        ***** No scaling
        *******************************************************

                iter:    0           residual = 1.000000e+00

    Solver:            cg
    number of iterations:    1

    Actual residual =  1.0000e-03    Recursive residual =  1.0000e-03

    Calculated Norms                Requested Norm
    --------------------------------------------    --------------

    ||r||_2 / ||r0||_2:        1.000000e+00    1.000000e-06


        Solution time: 0.000106 (sec.)
        total iterations: 1


    ***************************************************************

    Warning: direction vector is no longer A-conjugate
    to previous vector but solution has not converged.

    ***************************************************************