I am suspicious that he gets the exact same answer with a debug build.
You might try -O2 (and -O1, and -O0, which should be the same as your debug
build).
On Tue, Sep 17, 2019 at 2:21 PM Emmanuel Ayala via petsc-users <
petsc-users@mcs.anl.gov> wrote:
> OK, thanks for the clarification! :D
>
> R
OK, thanks for the clarification! :D
Regards.
El mar., 17 de sep. de 2019 a la(s) 13:16, Smith, Barry F. (
bsm...@mcs.anl.gov) escribió:
>
> In parallel the order of operations will always change with different
> number of processes; even with the same number the orders will be changed
> based
In parallel the order of operations will always change with different number
of processes; even with the same number the orders will be changed based on
order of arrival of data from other processes; so identical runs can produce
different results.
Barry
> On Sep 17, 2019, at 12:17 PM,
What do you mean by 2.0e-4 units ? If you mean the last 4 digits may differ
in the two solutions, yes that is completely normal. How many digits you lose
depends on the order of the operations and the condition number of the matrix
and and for elasticity that will very easily be greater
