[petsc-users] Problems about Picard and NolinearGS
Yingjie Wu
yjwu16 at gmail.com
Fri Jan 4 08:47:12 CST 2019
Thank you very much for your answer.
I tried to use the quasi-Newton method to solve some examples, except
ex48(in src/snes/example/tutorial), the ex3 and the ex19 will produce the
same error information. The error information is as follows. Is there
anything I should pay attention to when using the quasi-Newton method?
args: -snes_type qn -snes_qn_restart_type periodic -snes_qn_scale_type
jacobian
In ex3, it has a routine about Jacobian, while in ex19 without a Jacobian
routine.
Is the quasi-Newton method use the inverse of the initial Jacobian matrix
by finite difference ?
Error information in ex3:
mpiexec -n 2 ./ex3 -snes_type qn -snes_qn_restart_type periodic
-snes_qn_scale_type jacobian -snes_view
atol=1e-50, rtol=1e-08, stol=1e-08, maxit=10000, maxf=30000
iter = 0,SNES Function norm 5.41468
iter = 1,SNES Function norm 0.806152
iter = 2,SNES Function norm 0.459274
iter = 3,SNES Function norm 0.0562937
iter = 4,SNES Function norm 0.00756409
iter = 5,SNES Function norm 0.00153315
iter = 6,SNES Function norm 0.000108099
iter = 7,SNES Function norm 2.77778e-06
iter = 8,SNES Function norm 5.56429e-08
iter = 9,SNES Function norm 5.56429e-08
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Floating point exception
[0]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite
at beginning of function: Parameter number 2
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.10.1, Sep, 26, 2018
[0]PETSC ERROR: ./ex3 on a arch-linux2-c-debug named yjwu-XPS-8910 by yjwu
Fri Jan 4 09:11:00 2019
[0]PETSC ERROR: Configure options --with-cc=gcc --with-cxx=g++
--with-fc=gfortran --download-mpich --download-fblaslapack
[0]PETSC ERROR: #1 VecValidValues() line 26 in
/home/yjwu/petsc-3.10.1/src/vec/vec/interface/rvector.c
[0]PETSC ERROR: #2 SNESComputeFunction() line 2234 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[1]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[1]PETSC ERROR: Floating point exception
[1]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite
at beginning of function: Parameter number 2
[1]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[1]PETSC ERROR: Petsc Release Version 3.10.1, Sep, 26, 2018
[1]PETSC ERROR: ./ex3 on a arch-linux2-c-debug named yjwu-XPS-8910 by yjwu
Fri Jan 4 09:11:00 2019
[1]PETSC ERROR: Configure options --with-cc=gcc --with-cxx=g++
--with-fc=gfortran --download-mpich --download-fblaslapack
[1]PETSC ERROR: #1 VecValidValues() line 26 in
/home/yjwu/petsc-3.10.1/src/vec/vec/interface/rvector.c
[1]PETSC ERROR: #2 SNESComputeFunction() line 2234 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[1]PETSC ERROR: #3 SNESLineSearchApply_CP() line 48 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/impls/cp/linesearchcp.c
[1]PETSC ERROR: #4 SNESLineSearchApply() line 648 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/interface/linesearch.c
[0]PETSC ERROR: #3 SNESLineSearchApply_CP() line 48 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/impls/cp/linesearchcp.c
[0]PETSC ERROR: #4 SNESLineSearchApply() line 648 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/interface/linesearch.c
[0]PETSC ERROR: #5 SNESSolve_QN() line 403 in
/home/yjwu/petsc-3.10.1/src/snes/impls/qn/qn.c
[0]PETSC ERROR: [1]PETSC ERROR: #5 SNESSolve_QN() line 403 in
/home/yjwu/petsc-3.10.1/src/snes/impls/qn/qn.c
[1]PETSC ERROR: #6 SNESSolve() line 4396 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
#6 SNESSolve() line 4396 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[0]PETSC ERROR: [1]PETSC ERROR: #7 main() line 277 in
/home/yjwu/petsc-3.10.1/src/snes/examples/tutorials/ex3.c
#7 main() line 277 in
/home/yjwu/petsc-3.10.1/src/snes/examples/tutorials/ex3.c
[0]PETSC ERROR: PETSc Option Table entries:
[1]PETSC ERROR: PETSc Option Table entries:
[1]PETSC ERROR: [0]PETSC ERROR: -snes_qn_restart_type periodic
[0]PETSC ERROR: -snes_qn_restart_type periodic
[1]PETSC ERROR: -snes_qn_scale_type jacobian
[1]PETSC ERROR: -snes_qn_scale_type jacobian
[0]PETSC ERROR: -snes_type qn
[0]PETSC ERROR: -snes_type qn
[1]PETSC ERROR: -snes_view
-snes_view
[0]PETSC ERROR: ----------------End of Error Message -------send entire
error message to petsc-maint at mcs.anl.gov----------
[1]PETSC ERROR: ----------------End of Error Message -------send entire
error message to petsc-maint at mcs.anl.gov----------
application called MPI_Abort(MPI_COMM_WORLD, 72) - process 0
application called MPI_Abort(MPI_COMM_WORLD, 72) - process 1
Error information in ex19
mpiexec -n 2 ./ex19 -snes_type qn -snes_qn_restart_type periodic
-snes_qn_scale_type jacobian -snes_view
lid velocity = 0.0625, prandtl # = 1., grashof # = 1.
[0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[0]PETSC ERROR: Floating point exception
[0]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite
at beginning of function: Parameter number 2
[0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[0]PETSC ERROR: Petsc Release Version 3.10.1, Sep, 26, 2018
[0]PETSC ERROR: ./ex19 on a arch-linux2-c-debug named yjwu-XPS-8910 by yjwu
Fri Jan 4 09:05:10 2019
[1]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
[1]PETSC ERROR: Floating point exception
[1]PETSC ERROR: Vec entry at local location 0 is not-a-number or infinite
at beginning of function: Parameter number 2
[1]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for
trouble shooting.
[1]PETSC ERROR: Petsc Release Version 3.10.1, Sep, 26, 2018
[1]PETSC ERROR: ./ex19 on a arch-linux2-c-debug named yjwu-XPS-8910 by yjwu
Fri Jan 4 09:05:10 2019
[1]PETSC ERROR: Configure options --with-cc=gcc --with-cxx=g++
--with-fc=gfortran --download-mpich --download-fblaslapack
[1]PETSC ERROR: #1 VecValidValues() line 26 in
/home/yjwu/petsc-3.10.1/src/vec/vec/interface/rvector.c
[1]PETSC ERROR: [0]PETSC ERROR: Configure options --with-cc=gcc
--with-cxx=g++ --with-fc=gfortran --download-mpich --download-fblaslapack
[0]PETSC ERROR: #1 VecValidValues() line 26 in
/home/yjwu/petsc-3.10.1/src/vec/vec/interface/rvector.c
[0]PETSC ERROR: #2 SNESComputeFunction() line 2234 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[0]PETSC ERROR: #3 SNESLineSearchApply_CP() line 48 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/impls/cp/linesearchcp.c
[0]PETSC ERROR: #2 SNESComputeFunction() line 2234 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[1]PETSC ERROR: #3 SNESLineSearchApply_CP() line 48 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/impls/cp/linesearchcp.c
[1]PETSC ERROR: #4 SNESLineSearchApply() line 648 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/interface/linesearch.c
[1]PETSC ERROR: #4 SNESLineSearchApply() line 648 in
/home/yjwu/petsc-3.10.1/src/snes/linesearch/interface/linesearch.c
[0]PETSC ERROR: #5 SNESSolve_QN() line 403 in
/home/yjwu/petsc-3.10.1/src/snes/impls/qn/qn.c
[0]PETSC ERROR: #5 SNESSolve_QN() line 403 in
/home/yjwu/petsc-3.10.1/src/snes/impls/qn/qn.c
[1]PETSC ERROR: #6 SNESSolve() line 4396 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[1]PETSC ERROR: #7 main() line 161 in
/home/yjwu/petsc-3.10.1/src/snes/examples/tutorials/ex19.c
#6 SNESSolve() line 4396 in
/home/yjwu/petsc-3.10.1/src/snes/interface/snes.c
[0]PETSC ERROR: #7 main() line 161 in
/home/yjwu/petsc-3.10.1/src/snes/examples/tutorials/ex19.c
[0]PETSC ERROR: PETSc Option Table entries:
[1]PETSC ERROR: PETSc Option Table entries:
[1]PETSC ERROR: -snes_qn_restart_type periodic
[0]PETSC ERROR: -snes_qn_restart_type periodic
[0]PETSC ERROR: -snes_qn_scale_type jacobian
[0]PETSC ERROR: -snes_type qn
[1]PETSC ERROR: -snes_qn_scale_type jacobian
[1]PETSC ERROR: -snes_type qn
[0]PETSC ERROR: -snes_view
[0]PETSC ERROR: ----------------End of Error Message -------send entire
error message to petsc-maint at mcs.anl.gov----------
[1]PETSC ERROR: -snes_view
[1]PETSC ERROR: ----------------End of Error Message -------send entire
error message to petsc-maint at mcs.anl.gov----------
application called MPI_Abort(MPI_COMM_WORLD, 72) - process 0
application called MPI_Abort(MPI_COMM_WORLD, 72) - process 1
I am very interested in quasi-Newton method, which may not be well
understood at the moment.
I look forward to your reply.
Thanks,
Yingjie
Matthew Knepley <knepley at gmail.com> 于2019年1月3日周四 上午8:36写道：
> On Thu, Jan 3, 2019 at 7:36 AM Yingjie Wu via petsc-users <
> petsc-users at mcs.anl.gov> wrote:
>
>> Thanks for your reply.
>> I read the article you provided. This is my first contact with the
>> quasi-Newton method.
>> I have some problem:
>> 1. From the point of view of algorithm, the quasi-Newton method does not
>> need to be solved by linear equations, so why would KSP be used?
>>
>
> It is solving the equations, but we know the analytical answer. KSP is our
> abstraction for linear equation solver,
> so we also use it in this case.
>
>
>> 2. Where and how to use preconditioner in quasi-Newton method?
>>
>
> You do not need a PC here. Note that this is only going to work well if
> you have a good initial
> guess for the inverse of your Jacobian. The optimization people who
> invented have that (it is
> the identity). In Jed's paper, they use a V-cycle as the good initial
> guess.
>
> Thanks,
>
> Matt
>
>
>> Thanks,
>> Yingjie
>>
>> Jed Brown <jed at jedbrown.org> 于2018年12月27日周四 上午10:11写道：
>>
>>> Yingjie Wu via petsc-users <petsc-users at mcs.anl.gov> writes:
>>>
>>> > I my opinion, the difficulty in constructing my Jacobian matrix is
>>> complex
>>> > coefficient.(eg, thermal conductivity* λ* , density )
>>> > For example, in temperature equation(T):
>>> > ∇(*λ*∇T) - ∇(ρ* Cp* u ) + Q = 0
>>> > *λ* is thermal conductivity , ρ* is density Cp* is specific heat , u
>>> is
>>> > velocity, Q is source.
>>> > *λ = *1.9*(1.0e-3)*pow(T+273.0-150.0,1.29) function of T
>>> > ρ=
>>> >
>>> (0.4814*P/1.0e3/(T+273.15))/(1.0+0.446*(1.0e-2)*P/1.0e3/(pow(T+273.15,1.2)))
>>> > function of T and P
>>> >
>>> > In theory, the coefficient contain variable. So it is complicated to
>>> > calculate the element of Jacobian.
>>> > In my snes_mf_operator method, I treat λ,ρ as constant. In every
>>> nonlinear
>>> > step, I use the solution update the λ,ρ and thus update the
>>> > preconditioning matrix. At each residual function call(in
>>> > SNESFormFunction), I also update the coefficient to ensure the
>>> correction
>>> > of the residual function.
>>>
>>> If those Jacobian entries are really that hard to get right, you can try
>>> using quasi-Newton as an alternative to -snes_mf_operator; similar to
>>>
>>>
>>> https://jedbrown.org/files/BrownBrune-LowRankQuasiNewtonRobustJacobianLagging-2013.pdf
>>>
>>>
>>> In general, I would start with an exact Jacobian (computed by coloring,
>>> AD, or just in one specific material/configuration). Test Newton using
>>> direct solvers to see your "best case" convergence (globalization may be
>>> needed). Test fieldsplit using direct solvers on the blocks so you know
>>> how much error is attributable to that approximation. Only then look at
>>> backing off on the approximation of the Jacobian and the preconditioner.
>>>
>>
>
> --
> 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.cse.buffalo.edu/~knepley/>
>
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