> On Feb 22, 2015, at 9:32 AM, Jed Brown <[email protected]> wrote: > > Barry Smith <[email protected]> writes: >> Huhh? > > The smoothed interpolation satisfies > > P_{smoothed} = (1 - w D^{-1} A) P_{tentative} > > where D^{-1} is Jacobi (could be point-block Jacobi), but cannot be SOR. > GAMG is computing the estimate in order to choose w.
Jed, Wrong, wrong, wrong. You are looking at the wrong place in the code. (Yes, this is a problem with duplicate code in THREE! places). I am referring to the code around line 795 in gamg.c /* do my own cheby */ which I actually cut and pasted into my previous email. You are referring to the code in agg.c around line 1209 which does what you said. The code I am referring to computes the estimates used by the smoother on each level and thus forces a bypass of the code in Chebyshev.c it seems completely unneeded to me (aside from maybe the hack for crazy matrices) since Chebyshev.c will do it next automatically anyways. Barry > >> But anyways, even if GAMG turns on Cheby/Jacobi as the smoother >> there is not reason the Chebyshev estimator you wrote cannot be >> used since it just uses whatever PC has been set. So your response >> seems completely orthogonal to my question. Can we merge and just >> have one Chebyshev estimator? > > I think yes, after adding KSPChebyshevGetEigenvalues().
