Hi Andrew - we found a bug in TSComputeRHSFunctionLinear.
In your code you need to provide the context to TSSetRHSFunction:
TSSetRHSFunction( tss, NULL, TSComputeRHSFunctionLinear, &c );
For now you can check out a branch that has implemented the fix by
running git checkout emil/fix-ts-dae-rebased-v2 and then make everything.
The fix is at
https://bitbucket.org/petsc/petsc/commits/557d2b190687a728e86290bdc604ce0d2dc53473
This is working for us.
We'll push the fix soon in master.
Emil
--
Emil M. Constantinescu, Ph.D.
Computational Mathematician
Argonne National Laboratory
Mathematics and Computer Science Division
9700 S Cass Avenue,
Argonne, IL 60439, USA
Ph: 630-252-0926
http://www.mcs.anl.gov/~emconsta
On 3/30/15 9:32 PM, Andrew Spott wrote:
I’m sorry, I didn’t want to imply you were taking too much time. I was
just interested in trying to solve the problem myself, especially if it
was a simpler fix.
I don’t have enough of an understanding of the internals of PETSc
though, if it depends on the compiler flags.
Good luck!
-Andrew
—
Andrew
On Mon, Mar 30, 2015 at 7:23 PM, Emil Constantinescu
<emcon...@mcs.anl.gov <mailto:emcon...@mcs.anl.gov>> wrote:
Hi Andrew,
Sorry for the delay; things are going slower with me over the spring
break but we are working on it.
The problem that you see may not be related to the integrator, which
runs well (we get expected convergence rates and good results) for
other
problems, in particular, for problems with real variables (and no
c++11). So the high level th->endpoint implementation seems fine.
For some reason the linear solver is misbehaving when using cn. If you
use option -snes_mf the problem disappears.
Please do not use -ts_theta_adapt until it is fixed.
In conclusion I don't think that looking at theta.c will be productive.
We are currently looking at what happens at the lower levels.
Thanks,
Emil
On 3/30/15 4:25 PM, Andrew Spott wrote:
> Emil: If I want to fix this myself, do you have any idea where I
should
> start looking? I assume in the th->endpoint section of
TSStep_Theta in
>
http://www.mcs.anl.gov/petsc/petsc-current/src/ts/impls/implicit/theta/theta.c.html?
>
> Thanks,
>
> -Andrew
>
>
>
