[petsc-dev] -snes_check_jacobian

[Jed Brown]

Thank you, Peter.


On Thu, Dec 13, 2012 at 3:04 PM, Peter Brune <prbrune at gmail.com> wrote:

> Dangit Barry!  I already started a patch moving all Jed's -snes_compare_*
> garbage in SNESComputeJacobian() over to a SNESJacobianMonitor registration
> type deal where it has functions you can register to run after computing
> the Jacobian.  This will allow you to do all sorts of nice comparisons.
>
> Dangit Jed!  -snes_compare_* is a seeerious mess and shouldn't be in
> SNESComputeJacobian().  Barry's recent holy war against string comparisons
> will find this some day and there will be a lot of explaining to do.
>
> - Peter
>
>
>
> On Thu, Dec 13, 2012 at 4:59 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:
>
>> Surely you were aware of the -snes_compare_* options that can be
>> activated in SNESComputeJacobian().
>>
>> Can we settle on one common way to do this testing and perhaps remove
>> -snes_type test.
>>
>>
>> On Thu, Dec 13, 2012 at 2:55 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
>>
>>>
>>>    I got sick of -snes_type test only checking the Jacobian at the
>>> initial solution and not being able to test later Jacobians so I added
>>> -snes_check_jacobian that allows the regular running of SNESSolve() (also
>>> inside TS) and compares every Jacobian computed with a finite difference
>>> version.
>>>
>>>   For example, (already found one bug in one example :-(). This may be
>>> the best thing I've added to PETSc in a decade.
>>>
>>>    Barry
>>>
>>>
>>> Barrys-MacBook-Pro:advection-diffusion-reaction barrysmith$ ./ex1
>>> -snes_check_jacobian -snes_monitor  -ts_type arkimex | more
>>>     0 SNES Function norm 2.182384017537e+00
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       1.68322e-09 = ||J - Jfd||//J|| 6.69028e-06  = ||J - Jfd||
>>>     1 SNES Function norm 4.695397453383e-07
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       2.45109e-09 = ||J - Jfd||//J|| 9.74235e-06  = ||J - Jfd||
>>>     2 SNES Function norm 4.020379099215e-13
>>>     0 SNES Function norm 6.799718390407e-01
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       1.65487e-09 = ||J - Jfd||//J|| 6.5776e-06  = ||J - Jfd||
>>>     1 SNES Function norm 4.558192078678e-08
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       2.93714e-09 = ||J - Jfd||//J|| 1.16742e-05  = ||J - Jfd||
>>>     2 SNES Function norm 9.907308296870e-14
>>>     0 SNES Function norm 1.000842117652e+00
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       1.24476e-09 = ||J - Jfd||//J|| 4.94755e-06  = ||J - Jfd||
>>>     1 SNES Function norm 9.875108391772e-08
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       1.10818e-10 = ||J - Jfd||//J|| 4.40468e-07  = ||J - Jfd||
>>>     2 SNES Function norm 7.677760150017e-14
>>>     0 SNES Function norm 2.179048757949e+00
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       1.32338e-09 = ||J - Jfd||//J|| 5.27058e-07  = ||J - Jfd||
>>>     1 SNES Function norm 4.625448863612e-05
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>         Run with -snes_check_jacobian_display to show difference of
>>> hand-coded and finite difference Jacobian.
>>>       1.57582e-09 = ||J - Jfd||//J|| 6.27588e-07  = ||J - Jfd||
>>>     2 SNES Function norm 4.391784647745e-14
>>>     0 SNES Function norm 6.761591873515e-01
>>>         Testing hand-coded Jacobian, if the ratio is O(1.e-8), the
>>> hand-coded Jacobian is probably correct.
>>>
>>>
>>>
>>
>
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