Dear all, Just a few comments on the solvers, as I was searching for the one that would match my problem best. In PySparse it is LU, the default one, as was predictable cause I didn't see anything suspicious in the solution. In Trilinos it turned out to be LinearBicgstabSolver, although there are still some residuals left which I can push lower decreasing tolerance and residual limit while sweeping. LinearBicgstabSolve also turned out to be ~30% faster than Trilinos Deffault one. However, all this may just be specific to my problem.
> Well, as we say there, you *might* wish to make these changes. There is no > requirement not to use LU, just that GMRES is >generally better in Trilinos. > GMRES is broken in PySparse, so we can't use it there (and PySparse LU is > quite fast). I found GMRES working in PySparse. LU is excessively slow in Trilinos and does not solve anything (solution variable is 0 at each time step). I decided to try it first cause PySparse version is very good for my problem. I didn't try the ones for symmetric matrix, cause mine is asymmetric. > When comparing different solvers, you can be affected by different > preconditioners (and preconditioner settings), different solution > >tolerances, and different metrics for judging solution tolerance. For > instance, the default metrics used by PySparse PCG and >Trilinos PCG are > different. We probably need to decide whether FiPy's default settings should > force them to be identical or not. >Ultimately, that may not be possible; > these packages offer different capabilities. I have found that without Preconditioners all Solvers are noticeably slower. This may reflect what James said in one of the last posts. Regards, Igor.
