Hello again,

thanks a lot for the answers.

> When we set PySparse and Trilinos to both use the PCG solver without a 
> preconditioner and to use the same metric (b-vector) to gauge tolerance, we 
> find that they do an identical number of iterations and produce identical 
> residual vectors. I am thus not presently concerned about the results, just 
> the time. You earlier said you had cases were parallel produced different 
> answers from serial. We would definitely like to see examples of that so that 
> we can diagnose, because it has not been our experience.

After running the previous example, I repeated the exercise on my
problem and it turned out that different result I was talking about is
the consequence of Trilinos "DefaultAsymmetricSolver". I was using it
as was adviced at the FiPy web page. When I ran the script without mpi
explicitly saying to use Trilinos, the result was different from
Pysparse. I'm now trying to experiment with different solvers (for
Pysparse and Trilinos) and will report back what I found, but this
will probably be a matter of a different thread.

BTW, what does "DefaultAsymmetricSolver" stand for? Is it some *alias*
for some Solver from the manual? I didn't find explanation there...

Best Regards,
Igor.


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