On Wed, Dec 26, 2012 at 1:00 AM, amlan barua <abarua at iit.edu> wrote:
> Hi, > Greetings to the team! I am currently using PETSc for my research. Here is > a brief description of my problem and my query > a) I have a set a points distributed on a 3 dimensional lattice. > b) Corresponding to each point in this set, 7 odes are defined. > c) Of these 7 odes, 6 are uncoupled but one is coupled to nearest > neighbors. > I suggest not optimizing for "missing" coupling to start with. We can do the optimization in the solver, perhaps by splitting the DMDA into the local and coupled parts. > d) To integrate the odes I am using PETSc's DMDA and TS. But my > application needs implicit as well as locally high order solver. I am > looking for an implicit RK4 type method. Does PETSc have an IRK4 support or > equivalent? > If you are happy with a diagonally implicit method, you can use TSARKIMEX (these integrators can be IMEX, but can also do any diagonally implicit method). If you want a fully implicit RK (like Gauss, Radau IIA, etc) then all stages are coupled together. Those methods are not currently implemented in PETSc, though you could implement it either as a new TS implementation (good for code reuse; you can do this outside of PETSc, but the code you write is like library code) or manually using SNES (not reusable). > e) Suppose I want to build my own implicit time stepper. Should I imitate > ex2.c of SNES solver? > Thanks > Amlan > IISER Pune, India > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20121226/8d64e9fd/attachment.html>
