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 <[email protected]> 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>
