On Feb 18, 2014 10:12 AM, "Jed Brown" <[email protected]> wrote: > > Qin Lu <[email protected]> writes: > > > RCM did not help much for my case. This case represents some strong > > connectivities in channels. I am wondering if PETSc has some > > reordering algorithm or solver that is not based on connectivity > > graph, but is based on connectivity strength (such as percolation type > > of reordering). Any information is appreciated. Thanks, Qin > > There isn't such an ordering, but it would be a welcome contribution.
Not exactly. You can try 'wbm' in next. Matt > One challenge is that features like anisotropy are not necessarily > apparent in the matrix entries. In that case, and for vector-valued > problems, you would ideally use a better strength-of-connection measure. > If you computed a strength-of-connection, then thresholded (or used edge > weights as a "priority"), followed by something like an RCM ordering, > you could find something good for low-fill incomplete factorization in > problems with hidden anisotropy.
