[petsc-users] Issue of mg_coarse_ksp not converge

Mon Oct 2 10:15:29 CDT 2017

non-smoothed aggregation is converging very fast. smoothed fails in the
eigen estimator.

Run this again with -st_gamg_est_ksp_view and -st_gamg_est_ksp_monitor, and
see if you get more output (I'm not 100% sure about these args).

On Mon, Oct 2, 2017 at 11:06 AM, Wenbo Zhao <zhaowenbo.npic at gmail.com>
wrote:

> Matt,
>
> Test 1 nonsmooth
> zhaowenbo at ubuntu:~/test_slepc/SPARK/spark$ make NCORE=1 runkr_nonsmooth
> mpirun -n 1 ./step-41 \
>    -st_ksp_type gmres  -st_ksp_view -st_ksp_monitor  \
>    -st_pc_type gamg -st_pc_gamg_type agg -st_pc_gamg_agg_nsmooths 0 \
>    -mata AMAT.dat -matb BMAT.dat \
>    -eps_nev 1 -eps_ncv 10  -eps_monitor  -log_view > log_nonsmooth 2>&1
>
> Test 2 smooth
> zhaowenbo at ubuntu:~/test_slepc/SPARK/spark$ make NCORE=1 runkr_smooth
> mpirun -n 1 ./step-41 \
>    -st_ksp_type gmres -st_ksp_view -st_ksp_monitor  \
>    -st_pc_type gamg -st_pc_gamg_type agg -st_pc_gamg_agg_nsmooths 1 \
>    -mata AMAT.dat -matb BMAT.dat \
>    -eps_nev 1 -eps_ncv 10  -eps_monitor -log_view > log_smooth 2>&1
> makefile:43: recipe for target 'runkr_smooth' failed
> make: *** [runkr_smooth] Error 91
>
>
> Thanks,
>
> Wenbo
>
> On Mon, Oct 2, 2017 at 10:48 PM, Matthew Knepley <knepley at gmail.com>
> wrote:
>
>> On Mon, Oct 2, 2017 at 10:43 AM, Wenbo Zhao <zhaowenbo.npic at gmail.com>
>> wrote:
>>
>>> Mark,
>>>
>>> Thanks for your reply.
>>>
>>> On Mon, Oct 2, 2017 at 9:51 PM, Mark Adams <mfadams at lbl.gov> wrote:
>>>
>>>> Please send the output with -st_ksp_view and -st_ksp_monitor and we can
>>>> start to debug it.
>>>>
>>>> Test 1 with nonsmooth and preonly is OK
>>> zhaowenbo at ubuntu:~/test_slepc/SPARK/spark$ make NCORE=1 runkr_nonsmooth
>>> mpirun -n 1 ./step-41 \
>>>    -st_ksp_type gmres  -st_ksp_view -st_ksp_monitor  \
>>>    -st_pc_type gamg -st_pc_gamg_type agg -st_pc_gamg_agg_nsmooths 0 \
>>>    -st_ksp_view  -mata AMAT.dat -matb BMAT.dat \
>>>    -st_mg_coarse_ksp_type preonly   -st_mg_coarse_ksp_monitor  \
>>>    -eps_nev 1 -eps_ncv 10  -eps_monitor  -log_view > log_nonsmooth 2>&1
>>>
>>> Test 2 smooth and preonly is not OK
>>> zhaowenbo at ubuntu:~/test_slepc/SPARK/spark$ make NCORE=1 runkr_smooth
>>> mpirun -n 1 ./step-41 \
>>>    -st_ksp_type gmres -st_ksp_view -st_ksp_monitor  \
>>>    -st_pc_type gamg -st_pc_gamg_type agg -st_pc_gamg_agg_nsmooths 1 \
>>>    -st_ksp_view  -mata AMAT.dat -matb BMAT.dat \
>>>    -st_mg_coarse_ksp_type preonly   -st_mg_coarse_ksp_monitor  \
>>>    -eps_nev 1 -eps_ncv 10  -eps_monitor -log_view > log_smooth 2>&1
>>> makefile:43: recipe for target 'runkr_smooth' failed
>>> make: *** [runkr_smooth] Error 91
>>>
>>> Test 3 nonsmooth and gmres is not OK
>>> zhaowenbo at ubuntu:~/test_slepc/SPARK/spark$ make NCORE=1 runkr_gmres
>>> mpirun -n 1 ./step-41 \
>>>    -st_ksp_type gmres  -st_ksp_view -st_ksp_monitor  \
>>>    -st_pc_type gamg -st_pc_gamg_type agg -st_pc_gamg_agg_nsmooths 0 \
>>>    -st_ksp_view  -mata AMAT.dat -matb BMAT.dat \
>>>    -st_mg_coarse_ksp_type gmres  -st_mg_coarse_ksp_monitor
>>> -st_mg_coarse_ksp_rtol 1.0e-6 \
>>>
>>
>> DO NOT DO THIS. Please send the output where you do NOTHING to the coarse
>> solver.
>>
>>   Thanks,
>>
>>      Matt
>>
>>
>>>    -eps_nev 1 -eps_ncv 10  -eps_monitor  -log_view > log_gmres 2>&1
>>> makefile:59: recipe for target 'runkr_gmres' failed
>>> make: *** [runkr_gmres] Error 91
>>>
>>> log-files is attached.
>>>
>>>
>>> You mentioned that B is not symmetric. I assume it is elliptic
>>>> (diffusion). Where does the asymmetry come from?
>>>>
>>>>
>>> It is a two-group diffusion equations, where group denotes neutron
>>> enegry discretisation.
>>> Matrix B consists of neutron diffusion/leakage term, removal term and
>>> minus neutron scatter source term between different energies, when matrix A
>>> denotes neutron fission source.
>>>
>>> Diffusion term(Laplace operator) is elliptic and symmetric. Removal term
>>> is diagonal only. However scatter term is asymmetry since scatter term from
>>> high energy to low energy is far greater than the term from low to high.
>>>
>>>
>>> Wenbo
>>>
>>>
>>>> On Mon, Oct 2, 2017 at 9:39 AM, Wenbo Zhao <zhaowenbo.npic at gmail.com>
>>>> wrote:
>>>>
>>>>> Matt,
>>>>> Thanks for your reply.
>>>>> For the defalt option doesnt work firstly( -st_ksp_type gmres
>>>>> -st_pc_type gamg -st_pc_gamg_type agg -st_pc_gamg_agg_nsmooths 1), I tried
>>>>> to test those options.
>>>>>
>>>>> Wenbo
>>>>>
>>>>> On Mon, Oct 2, 2017 at 9:08 PM, Matthew Knepley <knepley at gmail.com>
>>>>> wrote:
>>>>>
>>>>>> On Mon, Oct 2, 2017 at 8:30 AM, Wenbo Zhao <zhaowenbo.npic at gmail.com>
>>>>>> wrote:
>>>>>>
>>>>>>> Matt
>>>>>>>
>>>>>>> Because I am not clear about what will happen using 'preonly' for
>>>>>>> large scale problem.
>>>>>>>
>>>>>>
>>>>>> The size of the problem has nothing to do with 'preonly'. All it
>>>>>> means is to apply a preconditioner without a Krylov solver.
>>>>>>
>>>>>>
>>>>>>> It seems to use a direct solver from below,
>>>>>>> http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/
>>>>>>> KSP/KSPPREONLY.html
>>>>>>>
>>>>>>
>>>>>> However, I still cannot understand why you would change the default?
>>>>>>
>>>>>>   Matt
>>>>>>
>>>>>>
>>>>>>>
>>>>>>> Thanks!
>>>>>>> Wenbo
>>>>>>>
>>>>>>> On Mon, Oct 2, 2017 at 5:09 PM, Matthew Knepley <knepley at gmail.com>
>>>>>>> wrote:
>>>>>>>
>>>>>>>> On Sun, Oct 1, 2017 at 9:53 PM, Wenbo Zhao <
>>>>>>>> zhaowenbo.npic at gmail.com> wrote:
>>>>>>>>
>>>>>>>>> Matt,
>>>>>>>>> Thanks for your reply.
>>>>>>>>> It DOES make no sense for this problem.
>>>>>>>>> But I am not clear about the 'preonly' option. Which solver is
>>>>>>>>> used in preonly? I wonder if 'preonly' is suitable for large scale problem
>>>>>>>>> such as 400,000,000 unknowns.
>>>>>>>>> So I tried 'gmres' option and found these error messages.
>>>>>>>>>
>>>>>>>>
>>>>>>>> I mean, why are you setting this at all. Just do not set the coarse
>>>>>>>> solver. The default should work fine.
>>>>>>>>
>>>>>>>>   Thanks,
>>>>>>>>
>>>>>>>>     Matt
>>>>>>>>
>>>>>>>>
>>>>>>>>> Could you give me some suggestions?
>>>>>>>>>
>>>>>>>>> Thanks.
>>>>>>>>>
>>>>>>>>> Wenbo
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Mon, Oct 2, 2017 at 12:34 AM, Matthew Knepley <
>>>>>>>>> knepley at gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>> On Sun, Oct 1, 2017 at 6:49 AM, Wenbo Zhao <
>>>>>>>>>> zhaowenbo.npic at gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> Hi,
>>>>>>>>>>>
>>>>>>>>>>> I met some questions when I use PETSC/SLEPC to solve two-group
>>>>>>>>>>> neutron diffusion equations with finite difference method. The grid is
>>>>>>>>>>> 3*3*3, when DOF on each points is 2. So the matrix size is 54*54.
>>>>>>>>>>> It is generalized eigenvalue problem Ax=\lamda Bx, where B is
>>>>>>>>>>> diagonally dominant matrix but not symmetry.
>>>>>>>>>>> EPS is set as below,
>>>>>>>>>>>  ierr = EPSSetProblemType(eps,EPS_GNHEP);CHKERRQ(ierr);¬
>>>>>>>>>>>  ierr = EPSSetWhichEigenpairs(eps,EPS_
>>>>>>>>>>> LARGEST_REAL);CHKERRQ(ierr);¬
>>>>>>>>>>>
>>>>>>>>>>> Krylovschur is used as eps sovler. GAMG is used as PC.
>>>>>>>>>>> I tried agg_nsmooths and mg_coarse_ksp_type. Only non-smooths
>>>>>>>>>>> and preonly is OK.
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Why are you setting the coarse solver. This makes no sense.
>>>>>>>>>>
>>>>>>>>>>    Thanks,
>>>>>>>>>>
>>>>>>>>>>     Matt
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Test 1
>>>>>>>>>>> $ make NCORE=1 runkr_nonsmooth
>>>>>>>>>>> mpirun -n 1 ./step-41 \
>>>>>>>>>>>    -st_ksp_type gmres  \
>>>>>>>>>>>    -st_pc_type gamg -st_pc_gamg_type agg
>>>>>>>>>>> -st_pc_gamg_agg_nsmooths 0 \
>>>>>>>>>>>    -st_ksp_view  -mata AMAT.dat -matb BMAT.dat \
>>>>>>>>>>>    -st_mg_coarse_ksp_type preonly   -st_mg_coarse_ksp_monitor  \
>>>>>>>>>>>    -eps_nev 1 -eps_ncv 10  -eps_monitor  -log_view >
>>>>>>>>>>> log_nonsmooth 2>&1
>>>>>>>>>>>
>>>>>>>>>>> Test 2
>>>>>>>>>>> $ make NCORE=1 runkr_smooth
>>>>>>>>>>> mpirun -n 1 ./step-41 \
>>>>>>>>>>>    -st_ksp_type gmres  \
>>>>>>>>>>>    -st_pc_type gamg -st_pc_gamg_type agg
>>>>>>>>>>> -st_pc_gamg_agg_nsmooths 1 \
>>>>>>>>>>>    -st_ksp_view  -mata AMAT.dat -matb BMAT.dat \
>>>>>>>>>>>    -st_mg_coarse_ksp_type preonly   -st_mg_coarse_ksp_monitor  \
>>>>>>>>>>>    -eps_nev 1 -eps_ncv 10  -eps_monitor -log_view > log_smooth
>>>>>>>>>>> 2>&1
>>>>>>>>>>> makefile:43: recipe for target 'runkr_smooth' failed
>>>>>>>>>>> make: *** [runkr_smooth] Error 91
>>>>>>>>>>>
>>>>>>>>>>> Test 3
>>>>>>>>>>> $ make NCORE=1 runkr_gmres
>>>>>>>>>>> mpirun -n 1 ./step-41 \
>>>>>>>>>>>    -st_ksp_type gmres  \
>>>>>>>>>>>    -st_pc_type gamg -st_pc_gamg_type agg
>>>>>>>>>>> -st_pc_gamg_agg_nsmooths 0 \
>>>>>>>>>>>    -st_ksp_view  -mata AMAT.dat -matb BMAT.dat \
>>>>>>>>>>>    -st_mg_coarse_ksp_type gmres  -st_mg_coarse_ksp_monitor
>>>>>>>>>>> -st_mg_coarse_ksp_rtol 1.0e-6 \
>>>>>>>>>>>    -eps_nev 1 -eps_ncv 10  -eps_monitor  -log_view > log_gmres
>>>>>>>>>>> 2>&1
>>>>>>>>>>> makefile:59: recipe for target 'runkr_gmres' failed
>>>>>>>>>>> make: *** [runkr_gmres] Error 91
>>>>>>>>>>>
>>>>>>>>>>> Log files were attched.
>>>>>>>>>>> The matrix file were also attched as AMAT.dat and BMAT.dat.
>>>>>>>>>>>
>>>>>>>>>>> Is it correct? Or something wrong with my code or commad-line?
>>>>>>>>>>>
>>>>>>>>>>> Thanks!
>>>>>>>>>>>
>>>>>>>>>>> Wenbo
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> --
>>>>>>>>>> What most experimenters take for granted before they begin their
>>>>>>>>>> experiments is infinitely more interesting than any results to which their
>>>>>>>>>> experiments lead.
>>>>>>>>>> -- Norbert Wiener
>>>>>>>>>>
>>>>>>>>>> https://www.cse.buffalo.edu/~knepley/
>>>>>>>>>> <http://www.caam.rice.edu/%7Emk51/>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> What most experimenters take for granted before they begin their
>>>>>>>> experiments is infinitely more interesting than any results to which their
>>>>>>>> experiments lead.
>>>>>>>> -- Norbert Wiener
>>>>>>>>
>>>>>>>> https://www.cse.buffalo.edu/~knepley/
>>>>>>>> <http://www.caam.rice.edu/%7Emk51/>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> What most experimenters take for granted before they begin their
>>>>>> experiments is infinitely more interesting than any results to which their
>>>>>> experiments lead.
>>>>>> -- Norbert Wiener
>>>>>>
>>>>>> https://www.cse.buffalo.edu/~knepley/
>>>>>> <http://www.caam.rice.edu/%7Emk51/>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>
>>
>> --
>> What most experimenters take for granted before they begin their
>> experiments is infinitely more interesting than any results to which their
>> experiments lead.
>> -- Norbert Wiener
>>
>> https://www.cse.buffalo.edu/~knepley/ <http://www.caam.rice.edu/~mk51/>
>>
>
>
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