Dear Wolfgang, dear community,
obviously this is a mistake. I checked the source files which we have used for
results in corresponding paper.
There I have found the following coding:
resid_old = resid;
resid_vector = system_rhs_newton;
resid_vector.compress(VectorOperation::insert);
int is_my_set_changed = (active_set == active_set_old) ? 0 : 1;
int num_changed = Utilities::MPI::sum(is_my_set_changed,
MPI_COMM_WORLD);
if (num_changed == 0 && resid < 1e-8)
break;
active_set_old = active_set;
Unfortunately I have not been working with deal.ii for over two years now.
For this reason I would be glad if someone else could fix this bug.
Otherwise I would need a short manual how to do it by myself.
With the best wishes for the future for deal.ii and their developers!
Joerg
________________________________________
Von: Wolfgang Bangerth [bange...@colostate.edu]
Gesendet: Dienstag, 16. Januar 2018 21:48
An: dealii@googlegroups.com; Frohne, Joerg
Cc: Suttmeier, Franz-Theo
Betreff: Re: [deal.II] step-42 clarification
On 01/16/2018 12:59 AM, Alberto Salvadori wrote:
> Dear community,
>
> I am studying with pleasure step-42 and I got a bit confused in the
> method PlasticityContactProblem::solve_newton. At the very end of it, we
> find these instructions:
>
> old_active_set = active_set;
> previous_residual_norm = residual_norm;
> if (Utilities::MPI::sum
> <http://www.dealii.org/8.5.0/doxygen/deal.II/namespaceUtilities_1_1MPI.html#ab544a3bf3301a6dd3e705ee352c5551b>((active_set
> == old_active_set) ? 0 : 1,
> mpi_communicator) == 0)
> {
> pcout << " Active set did not change!" << std::endl;
> if (residual_norm < 1e-10)
> break;
> }
>
>
> Now, I am a bit confused by the if statement and I am clearly missing
> something. The first instruction makes old_active_set equal to
> active_set. Accordingly, wouldn't active_set == old_active_set always
> be true? What am I missing?
You're right -- the code would suggest that the if-condition is always
true and that what matter is only the inner if.
I'm not sure I have the current email address of Joerg Frohne who wrote
step-42. He would be the one who could possibly provide a better answer.
Best
W.
--
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Wolfgang Bangerth email: bange...@colostate.edu
www: http://www.math.colostate.edu/~bangerth/
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