[petsc-users] SuperLU convergence problem

[Hong]

Danyang :
Further testing a_flow_check_168.bin,
./ex10 -f0 /Users/Hong/Downloads/matrix_and_rhs_bin/a_flow_check_168.bin
-rhs /Users/Hong/Downloads/matrix_and_rhs_bin/x_flow_check_168.bin -pc_type
lu -pc_factor_mat_solver_package superlu -ksp_monitor_true_residual
-mat_superlu_conditionnumber
  Recip. condition number = 1.610480e-12
  0 KSP preconditioned resid norm 6.873340313547e+09 true resid norm
7.295020990196e+03 ||r(i)||/||b|| 1.000000000000e+00
  1 KSP preconditioned resid norm 2.051833296449e-02 true resid norm
2.976859070118e-02 ||r(i)||/||b|| 4.080672384793e-06
Number of iterations =   1
Residual norm 0.0297686

condition number of this matrix = 1/1.610480e-12 = 1.e+12,
i.e., this matrix is ill-conditioned.

Hong


Hi Hong,
>
> The binary format of matrix, rhs and solution can be downloaded via the
> link below.
>
> https://www.dropbox.com/s/cl3gfi0s0kjlktf/matrix_and_rhs_bin.tar.gz?dl=0
>
> Thanks,
>
> Danyang
>
>
> On 15-12-03 10:50 AM, Hong wrote:
>
> Danyang:
>
>>
>>
>> To my surprising, solutions from SuperLU at timestep 29 seems not correct
>> for the first 4 Newton iterations, but the solutions from iteration solver
>> and MUMPS are correct.
>>
>> Please find all the matrices, rhs and solutions at timestep 29 via the
>> link below. The data is a bit large so that I just share it through
>> Dropbox. A piece of matlab code to read these data and then computer the
>> norm has also been attached.
>> *https://www.dropbox.com/s/rr8ueysgflmxs7h/results-check.tar.gz?dl=0
>> <https://www.dropbox.com/s/rr8ueysgflmxs7h/results-check.tar.gz?dl=0>*
>>
>
> Can you send us matrix in petsc binary format?
>
> e.g., call MatView(M, PETSC_VIEWER_BINARY_(PETSC_COMM_WORLD))
> or '-ksp_view_mat binary'
>
> Hong
>
>>
>>
>> Below is a summary of the norm from the three solvers at timestep 29,
>> newton iteration 1 to 5.
>>
>> Timestep 29
>> Norm of residual seq 1.661321e-09, superlu 1.657103e+04, mumps
>> 3.731225e-11
>> Norm of residual seq 1.753079e-09, superlu 6.675467e+02, mumps
>> 1.509919e-13
>> Norm of residual seq 4.914971e-10, superlu 1.236362e-01, mumps
>> 2.139303e-17
>> Norm of residual seq 3.532769e-10, superlu 1.304670e-04, mumps
>> 5.387000e-20
>> Norm of residual seq 3.885629e-10, superlu 2.754876e-07, mumps
>> 4.108675e-21
>>
>> Would anybody please check if SuperLU can solve these matrices? Another
>> possibility is that something is wrong in my own code. But so far, I cannot
>> find any problem in my code since the same code works fine if I using
>> iterative solver or direct solver MUMPS. But for other cases I have
>> tested,  all these solvers work fine.
>>
>> Please let me know if I did not write down the problem clearly.
>>
>> Thanks,
>>
>> Danyang
>>
>>
>>
>>
>
>
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