Based on my reading of the attached paper, in particular the last line on page 1050 I don't think it matters.
and P−1A and AP−1 have the minimal polynomial (λ − 1)2. since the application on either side matches the same polynomial. Barry
s1064827500377435.pdf
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> On Jun 23, 2017, at 11:48 AM, Hoang Giang Bui <[email protected]> wrote: > > Hello > > I just want to make sure that I understand the right thing, in the manual > page of PCFieldSplitSetSchurFactType: > http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCFieldSplitSetSchurFactType.html > > The "upper" option uses DU from the full factorization. If I understand > correctly, the ksp must be used with right preconditioning, because A P^-1 = > (LDU) * (DU)^(-1) = L. If that was the case, should the manual put this > information to be more clear? > > Thanks > Giang >
