FETIDP is in PETSc as a byproduct of the BDDC preconditioner (one is the dual of the other) and it does not have its own classes so far.
That said, you can experiment with FETI-DP only after having setup a BDDC preconditioner with the options and customization you prefer. Use http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/KSP/index.html for manual pages. For an 'how to' with FETIDP, please see src/ksp/ksp/examples/tutorials/ex.59.c as Jed told you, specifically look at ComputeKSPFETIDP for obtaining the FETIDP matrix F (implemented Matrix-free) and the optimal FETIDP dirichlet preconditioner. Once you have F, you can use PCBDDCMatFETIDPGetRHS and PCBDDCMatFetiDPGetSolution to obtain a right-hand side for the FETIDP system and a physical solution from the solution of the FETIDP system. I would recommend you to use the development version of the library and either use the ‘next’ branch or the ‘master' branch after having merged in the branch stefano_zampini/pcbddc-primalfixes. Note that ‘next’ also contains the new deluxe scaling operator for BDDC which is not available to use with FETI-DP. If you have any other questions which can be useful for other PETSc users, please use the mailing list; otherwise you can contact me personally. Stefano On Sep 3, 2014, at 5:19 PM, Jed Brown <[email protected]> wrote: > Matthew Knepley <[email protected]> writes: >>> 1- Is it possible to complete a FETI-DP solution with the provided >>> functions in current PetSc release? >>> >> >> There is no FETI-DP in PETSc. > > Wrong. There is PCBDDC, which has the same eigenvalues as FETI-DP. You > can enable it by configuring --with-pcbddc. This will be turned on by > default soon. It is fairly new, so you should use the branch 'master' > instead of the release. It has an option to do FETI-DP instead of BDDC. > See src/ksp/ksp/examples/tutorials/ex59.c. > > For either of these methods, you have to assemble a MATIS. If you use > MatSetValuesLocal, most of your assembly code can stay the same. > > Hopefully we can get better examples before the next release. Stefano > (the author of PCBDDC, Cc'd) tests mostly with external packages, but we > really need more complete tests within PETSc.
