About SNES solver of TS objects

[Lisandro Dalcin]

BTW, perhaps you should do the same in TSGetKSP(). What do you think?

2008/9/17 Hong Zhang <hzhang at mcs.anl.gov>:
>
> TSGetSNES() must be called after TSSetType(),
> otherwise the nonlinear context 'snes' is
> being created.
> Attached please find updated ex7.c, which
> illustrates how to set uer-defined SNESMonitor().
>
> This example is pushed to petsc-dev.
> I also added an error flag in petsc-dev to prevent
> calling of TSGetSNES() before TSSetType().
> Thanks for reporting the problem!
>
> Best,
>
> Hong
>
> On Fri, 12 Sep 2008, tsjb00 wrote:
>
>>
>> Many thanks for your reply! The code I tried was very similar to the code in:
>> ts/examples/tutorials/ex7.c
>> except that I changed the r.h.s. function.
>>
>> The code related to TS:
>>     ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
>>     ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
>>     ierr = TSSetRHSFunction(ts,FormFunction,&appctx);CHKERRQ(ierr);
>>
>>     ierr = DAGetColoring(appctx.da,IS_COLORING_GLOBAL,&iscoloring);CHKERRQ(ierr);
>>     ierr = MatFDColoringCreate(J,iscoloring,&matfdcoloring);CHKERRQ(ierr);
>>     ierr = ISColoringDestroy(iscoloring);CHKERRQ(ierr);
>>     ierr = MatFDColoringSetFunction(matfdcoloring,(PetscErrorCode (*)(void))FormFunction,&appctx);CHKERRQ(ierr);
>>     ierr = MatFDColoringSetFromOptions(matfdcoloring);CHKERRQ(ierr);
>>     ierr = TSSetRHSJacobian(ts,J,J,TSDefaultComputeJacobianColor,matfdcoloring);CHKERRQ(ierr);
>>
>>     dt = appctx.dtmin;
>>     ierr = TSSetInitialTimeStep(ts,0.0,dt);CHKERRQ(ierr);
>>      ierr = TSSetType(ts,TS_BEULER);CHKERRQ(ierr);
>>
>> Then I tried to add the snes monitor:
>>   PetscViewerASCIIOpen(PETSC_COMM_WORLD,"snes.log",&rviewer);
>>    ierr = TSGetSNES(ts,&ts_snes);
>>    ierr = SNESMonitorSet(ts_snes,SNESMonitorDefault,&rviewer,PETSC_NULL);
>> I got the snes.log with long lines which started with countless blank/space and ended at the very end with the SNES iteration info.  As a result, the file took a lot of memory space even with one line of outputs.
>>
>> Please let me know if I did something wrong.
>>
>> Have a nice weekend!
>>
>>
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-- 
Lisandro Dalcín
---------------
Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
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