Thanks. I got it. For the moment I have some general questions.
- I see that in this example all terms--diffusion and reactions--are put into RHSFunction. There is no IFunction. Is there a reason for that ? In which cases one should use IFunction or RHSFunction ? In ts/.../ex25.c, diffusion terms are defined in IFunction and reaction terms in RHSFunction. Why not here ? - If only RHSFunction is used, how is it possible to define boundary conditions ? For instance, a Dirichlet boundary condition, u(i=0)=3. In ts/.../ex2.c, only RHSFunction is used and the boundary conditions are defined through u_t, - In this type of problem, which TS scheme is recommended ? TSARKIMEX ? - The option TSARKIMEXSetFullyImplicit is used. Why ? Does it help ? Christophe CIEMAT Laboratorio Nacional de Fusión por Confinamiento Magnético Unidad de Materiales Edificio 2 - Planta 0 - Despacho 28m Avenida Complutense 40, 28040 Madrid, Spain Tel: +34 91496 2582 Fax: +34 91346 6442 -- Q Por favor, piense en el medio ambiente antes de imprimir este mensaje. Please consider the environment before printing this email. On Mon, Oct 7, 2013 at 3:23 PM, Barry Smith <[email protected]> wrote: > > I have put it into the next branch. So just download petsc from the > bitbucket site with git and then do git checkout next > > The code won't work with the current PETSc release. > > On Oct 7, 2013, at 8:16 AM, Christophe Ortiz <[email protected]> > wrote: > > > Hi Barry, > > > > Thanks for the reply. > > > > I had a look at the example ex10.c. But I see it does not fully > corresponds to what one can see in the branch. For instance, in the example > that is found in the tutorials, there is no RHS defined, no Jacobian, just > the IFunction. > > > > Could you please send me the latest version of ex10.c ? Many thanks in > advance. > > > > Christophe > > > > CIEMAT > > Laboratorio Nacional de Fusión por Confinamiento Magnético > > Unidad de Materiales > > Edificio 2 - Planta 0 - Despacho 28m > > Avenida Complutense 40, > > 28040 Madrid, Spain > > Tel: +34 91496 2582 > > Fax: +34 91346 6442 > > > > -- > > Q > > Por favor, piense en el medio ambiente antes de imprimir este mensaje. > > Please consider the environment before printing this email. > > > > > > On Mon, Oct 7, 2013 at 2:00 PM, Barry Smith <[email protected]> wrote: > > > > Chris, > > > > Take a look in the petsc branch barry/wirth-fusion-materials > https://bitbucket.org/petsc/petsc/branch/barry%2Fwirth-fusion-materials > > in the file > src/ts/examples/tutorials/advection-diffusion-reaction/ex10.c feel free > to ask any questions. > > > > Barry > > > > On Oct 7, 2013, at 3:03 AM, Christophe Ortiz <[email protected]> > wrote: > > > > > Hi all > > > > > > I need some suggestions to design a code with PETSc. > > > > > > I want to solve a 1D problem composed of several diffusion equations > and a lot of ODEs (thousands). > > > > > > - After discretization, the diffusion equations have terms in i-1, i > and i+1. > > > > > > - The diffusion equations have additional terms due to couping with > all the ODEs. These terms are non-linear. > > > > > > - The terms of the ODEs are local (only depend on node i) but are > non-linear. > > > > > > Any advice to design the code ? > > > > > > How should I distribute the terms between IFunction and RHSFunction ? > > > > > > Any special attention to DMDA ? Should I declare just one DMDA with > dof >>1 ? > > > > > > Many thanks in advance ! > > > Christophe > > > > > > > > >
