[petsc-dev] -snes_check_jacobian

[Jed Brown]

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.
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20121213/6784addf/attachment.html>