This problem still exists. What do we do? Broken code that a beginner could easily start with is not a good thing.
Barry > On Feb 27, 2016, at 5:21 PM, Barry Smith <[email protected]> wrote: > > > Jed and Emil, > > Yes, this is a terrible mess. The TSComputeRHSJacobianConstant() will only > work for methods that do not change entries in the Jacobian matrix. And for > some reason the runex3_4 and _5 which do not work are turned off in the > makefile ! It looks like Rosw does work because it does not change the > matrix? And yet it is still turned off? > > I don't know what a good fix is. If we want to keep this capability then > the TSComputeRHSJacobianConstant() interface has to keep a copy of the > original user provided matrix and copy it into the matrices used by the > method each time. This may lead to ugly special case code. > > Something has to be done about (simplest thing is just tossing the entire > concept) because now there is a very broken API in TS that beginning users > are likely to try and get upset with. > > Barry > > >> On Feb 26, 2016, at 11:04 AM, Dominic Meiser <[email protected]> wrote: >> >> Hi all, >> >> I'm running into problems with TS with a time independent, linear >> rhs. Following the user's manual, I use >> >> ierr=TSSetProblemType(ts, TS_LINEAR);CHKERRQ(ierr); >> ierr=TSSetRHSFunction(ts, 0, TSComputeRHSFunctionLinear, 0);CHKERRQ(ierr); >> ierr=TSSetRHSJacobian(ts, mat, mat, TSComputeRHSJacobianConstant, >> 0);CHKERRQ(ierr); >> >> But running the code I get: >> >> [dmeiser@ivyamd src]$ ./sd -ts_monitor -snes_monitor >> -ksp_monitor_true_residual -snes_converged_reason -ts_type beuler >> -ts_max_steps 20 TS dt 0.01 time 0. >> 0 SNES Function norm 1.433485640883e+00 >> 0 KSP preconditioned resid norm 1.433485640883e-02 true resid norm >> 1.433485640883e+00 ||r(i)||/||b|| 1.000000000000e+00 >> 1 KSP preconditioned resid norm 6.528150237447e-18 true resid norm >> 6.122666587510e-16 ||r(i)||/||b|| 4.271173992185e-16 >> 1 SNES Function norm 1.419007435910e+02 >> Nonlinear solve converged due to CONVERGED_ITS iterations 1 >> 1 TS dt 0.01 time 0.01 >> 0 SNES Function norm 1.433342292319e+02 >> Nonlinear solve did not converge due to DIVERGED_LINEAR_SOLVE iterations 0 >> [0]PETSC ERROR: --------------------- Error Message >> -------------------------------------------------------------- >> [0]PETSC ERROR: >> [0]PETSC ERROR: TSStep has failed due to DIVERGED_NONLINEAR_SOLVE, increase >> -ts_max_snes_failures or make negative to attempt recovery >> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for >> trouble shooting. >> [0]PETSC ERROR: Petsc Development GIT revision: pre-tsfc-330-gda8116b GIT >> Date: 2016-02-23 15:17:17 -0600 >> [0]PETSC ERROR: ./sd on a cplx named ivyamd.txcorp.com by dmeiser Fri Feb 26 >> 11:46:29 2016 >> [0]PETSC ERROR: Configure options --with-scalar-type=complex --with-x=0 >> --with-debugging=1 --with-ssl=0 --with-fortran-kernels=0 --with-pthread=0 >> --download-fftw=1 --with-mpi=1 --download-mpich=1 >> --with-mpiuni-fortran-binding=0 --with-fortran-interfaces >> [0]PETSC ERROR: #1 TSStep() line 3346 in >> /scr_ivyamd/dmeiser/SD/petsc/src/ts/interface/ts.c >> [0]PETSC ERROR: #2 TSSolve() line 3544 in >> /scr_ivyamd/dmeiser/SD/petsc/src/ts/interface/ts.c >> [0]PETSC ERROR: #3 main() line 63 in /scr_ivyamd/dmeiser/SD/src/sd.c >> [0]PETSC ERROR: PETSc Option Table entries: >> [0]PETSC ERROR: -ksp_monitor_true_residual >> [0]PETSC ERROR: -snes_converged_reason >> [0]PETSC ERROR: -snes_monitor >> [0]PETSC ERROR: -ts_max_steps 2 >> [0]PETSC ERROR: -ts_monitor >> [0]PETSC ERROR: -ts_type beuler >> [0]PETSC ERROR: ----------------End of Error Message -------send entire >> error message to [email protected] >> application called MPI_Abort(MPI_COMM_WORLD, 91) - process 0 >> [unset]: aborting job: >> application called MPI_Abort(MPI_COMM_WORLD, 91) - process 0 >> >> >> It seems that the linear system is being solved just fine. But >> apparently it's the wrong linear problem because the SNES >> function norm doesn't decrease. >> >> I think the problem might be related to the following behaviour >> of `scr/ts/examples/tutorials/ex3.c`: >> >> >> [dmeiser@ivyamd tutorials]$ ./ex3 -nox -ts_type beuler -ts_max_steps 2 >> -ksp_converged_reason -snes_monitor >> Solving a linear TS problem on 1 processor >> Timestep 0: step size = 0.000143637, time = 0., 2-norm error = >> 1.01507e-15, max norm error = 3.10862e-15 >> 0 SNES Function norm 2.018485956680e+03 >> Linear solve converged due to CONVERGED_RTOL iterations 1 >> 1 SNES Function norm 1.207665524289e+05 >> Timestep 1: step size = 0.000143637, time = 0.000143637, 2-norm error = >> 0.000599907, max norm error = 0.000863771 >> 0 SNES Function norm 1.195422385486e+05 >> Linear solve did not converge due to DIVERGED_PCSETUP_FAILED iterations 0 >> PCSETUP_FAILED due to FACTOR_NUMERIC_ZEROPIVOT >> [0]PETSC ERROR: --------------------- Error Message >> -------------------------------------------------------------- >> [0]PETSC ERROR: >> [0]PETSC ERROR: TSStep has failed due to DIVERGED_NONLINEAR_SOLVE, increase >> -ts_max_snes_failures or make negative to attempt recovery >> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for >> trouble shooting. >> [0]PETSC ERROR: Petsc Development GIT revision: pre-tsfc-330-gda8116b GIT >> Date: 2016-02-23 15:17:17 -0600 >> [0]PETSC ERROR: ./ex3 on a cplx named ivyamd.txcorp.com by dmeiser Fri Feb >> 26 11:36:28 2016 >> [0]PETSC ERROR: Configure options --with-scalar-type=complex --with-x=0 >> --with-debugging=1 --with-ssl=0 --with-fortran-kernels=0 --with-pthread=0 >> --download-fftw=1 --with-mpi=1 --download-mpich=1 >> --with-mpiuni-fortran-binding=0 --with-fortran-interfaces >> [0]PETSC ERROR: #1 TSStep() line 3346 in >> /scr_ivyamd/dmeiser/SD/petsc/src/ts/interface/ts.c >> [0]PETSC ERROR: #2 TSSolve() line 3544 in >> /scr_ivyamd/dmeiser/SD/petsc/src/ts/interface/ts.c >> [0]PETSC ERROR: #3 main() line 216 in >> /scr_ivyamd/dmeiser/SD/petsc/src/ts/examples/tutorials/ex3.c >> [0]PETSC ERROR: PETSc Option Table entries: >> [0]PETSC ERROR: -ksp_converged_reason >> [0]PETSC ERROR: -nox >> [0]PETSC ERROR: -snes_monitor >> [0]PETSC ERROR: -ts_max_steps 2 >> [0]PETSC ERROR: -ts_type beuler >> [0]PETSC ERROR: ----------------End of Error Message -------send entire >> error message to [email protected] >> application called MPI_Abort(MPI_COMM_WORLD, 91) - process 0 >> [unset]: aborting job: >> application called MPI_Abort(MPI_COMM_WORLD, 91) - process 0 >> >> >> I'm aware of Jed's commit e1244c6 which I thought was supposed to >> enable constant linear rhs without IFunction and IJacobian. Note >> that e1244c6 also added tests that apparently produced very >> different output (see e.g. >> src/ts/examples/tutorials/output/ex3_4.out). >> >> Is constant rhs without IFunction and IJacobian no longer >> supported or did it just breat at some point? Do I need to call >> TSRHSJacobianSetReuse in addition to the lines of code above? Is >> it better to treat such systems using TSComputeIFunctionLinear >> and TSComputeIJacobianConstant? >> >> Thanks, >> Dominic >> >> -- >> Dominic Meiser >> Tech-X Corporation - 5621 Arapahoe Avenue - Boulder, CO 80303 >
