[petsc-dev] Yet more KSPs

Victor Eijkhout eijkhout at cs.utk.edu
Thu Apr 22 14:33:12 CDT 2010

On 2010/04/12, at 1:28 AM, Matthew Knepley wrote:

> Someone has gone the extra mile and made an A-orthogonal Lanczos
>   http://arxiv.org/pdf/1004.1622v1

Is that hard? Basically a slightly different inner product. A- 
orthogonalization gives L2 minimal residuals. (Under the ordinary  
inner product the residuals are minimal in the A^{-1} norm)

> It appears to outperform BiCGStab in enough of their tests

That might be true since BiCGS is based on the ordinary Lanczos / BiCG.

Hm. Why not do an A-orthogonal BicGstab. Hold on. Let me grab some  
scrap paper.....



Victor Eijkhout -- 865 974 9308
eijkhout at cs.utk.edu http://www.cs.utk.edu/~eijkhout/

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