On Mon, May 19, 2014 at 3:57 AM, Jonathan Wong <[email protected]>wrote:
> I'm running into an issue for a symmetric (may not be pd) finite element > problem where I am using the cg method and getting an indefinite_mat or > indefinite_pc error using the jacobi preconditioner. If I change the pc > type to bjacobi, it converges nicely. I am only using 1 process, and I > assumed they would produce the same result, as I'm using default options. > > Does anyone have any ideas why this would happen? > No, Block-Jacobi and Jacobi are completely different. If you are not positive definite, you should be using MINRES. Matt > It also works fine with gmres + jacobi pc. > > Thanks, > Jon > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
