-snes_type test

[Matthew Knepley]

You could calculate an index incorrectly. Pick the first value that is
different.
Follow the entire computation by hand.

  Matt

On Tue, Apr 21, 2009 at 2:05 PM, (Rebecca) Xuefei YUAN
<xy2102 at columbia.edu>wrote:

> Hi,
>
> I am testing my hand coded jacobian matrix in multi processors with the
> option "-snes_type test -snes_test_display", and I find that
> 1) my hand coded jacobian is different from the finite difference jacobian
> running with 2 processors.
> But
> 2) my jacobian is the same as the finite difference jacobian matrix running
> with 1 single processor.
> Also
> 3) my hand coded jacobian with 1 processor is the same as my hand coded
> jacobian with 2 processors.
>
> Where could be wrong about multiprocessors' jacobian matrix?
>
> Thanks very much!
> --
> (Rebecca) Xuefei YUAN
> Department of Applied Physics and Applied Mathematics
> Columbia University
> Tel:917-399-8032
> www.columbia.edu/~xy2102 <http://www.columbia.edu/%7Exy2102>
>
>


-- 
What most experimenters take for granted before they begin their experiments
is infinitely more interesting than any results to which their experiments
lead.
-- Norbert Wiener
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