[petsc-users] arkimex rejecting all dt in petsc 3.6.0

[Barry Smith]

  Here is the response from Emil who made the changes to the code

If you are solving a DAE then in the new version, we introduced a new flag that distinguishes between ODEs and DAEs leading to different semantics. For DAEs this is needed b/c it may not have consistent initial conditions.

If solving DAEs, the user has to set the EquationType appropriately:
e.g.,
ierr = TSSetEquationType(ts,TS_EQ_DAE_IMPLICIT_INDEX1);CHKERRQ(ierr);

This is documented in the doc, but I didn't add it to the changelog (Jed pointed it out to me).

Currently it only affects -ts_type arkimex. I'll work with Satish to add it to the changelog.

*If that's not the case:* let me know and we can dig deeper.

Emil

> On Jun 18, 2015, at 5:48 AM, Italo Tasso <italo at tasso.com.br> wrote:
> 
> I just upgraded to 3.6.0 and my code stopped working. All dt are rejected. I used the same configure line, same code, same everything.
> 
> With 3.5.4 I get:
> 
> 0 TS dt 1e-06 time 0
>     0 SNES Function norm 2.549981005316e+05
>     1 SNES Function norm 6.107056905987e-03
>     2 SNES Function norm 1.483881932064e-10
>     3 SNES Function norm 9.122873794272e-11
>   Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 3
>     0 SNES Function norm 7.790429171165e+04
>     1 SNES Function norm 7.289068747803e-04
>     2 SNES Function norm 8.227639633330e-11
>   Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 2
>     0 SNES Function norm 1.154356516184e+05
>     1 SNES Function norm 2.309925413255e-03
>     2 SNES Function norm 6.382141981406e-11
>   Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 2
>       TSAdapt 'basic': step   0 accepted t=0          + 1.000e-06 wlte=0.000654 family='arkimex' scheme=0:'3' dt=1.000e-05
> 
> With 3.6.0 I get:
> 
> 0 TS dt 1e-06 time 0
>     0 SNES Function norm 2.549981005316e+05
>     1 SNES Function norm 6.107056925316e-03
>     2 SNES Function norm 1.519319591792e-10
>     3 SNES Function norm 9.070104116945e-11
>   Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 3
>     0 SNES Function norm 7.790429171165e+04
>     1 SNES Function norm 6.942541792651e-04
>     2 SNES Function norm 8.458781909516e-11
>   Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 2
>     0 SNES Function norm 1.154356516184e+05
>     1 SNES Function norm 2.287202942961e-03
>     2 SNES Function norm 6.585201377573e-11
>   Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 2
>       TSAdapt 'basic': step   0 rejected t=0          + 1.000e-06 wlte=  324 family='arkimex' scheme=0:'3' dt=1.311e-07
> 
> Any ideas? I attached the full output.
> 
> Options I use:
> 
> -ts_view -ts_type arkimex -ts_arkimex_fully_implicit -ts_adapt_monitor -ts_monitor -snes_monitor -snes_converged_reason -ksp_type preonly -pc_type lu -pc_factor_mat_solver_package mumps -snes_rtol 0 -snes_atol 1e-10 -snes_stol 0
> 
> <petsc354.txt><petsc360.txt>