On Thu, 21 Feb 2008, Benjamin Kirk wrote: >>> I want to solve a pde equation involving a parameter to be incremented >>> sucessively. After obtaining a solution I want to use it as a guess for >>> the system to be solved next. How can I implement this? > >> I'm not an expert on Libmesh, but I recall that PETSC allows one to >> set the iinitial guess. If PETSc can be accessed through the libmesh >> interface then it should be possible quite easily. > > Indeed it is -- this is in fact the default behavior in libMesh. Whatever > is in the System.solution vector is handed off to the linear solver as the > initial guess. You should be able to verify this by calling > > equation_systems.solve(); > equation_systems.solve(); > > And seeing that the second solve converges in 0 iterations.
Wait, doesn't that depend on your tolerance settings? If you're using a relative residual reduction, the second solve will start from a smaller initial residual than the first solve, and will have to do work to make that residual even smaller. --- Roy ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
