> > In src/ksp/ksp/examples/tutorials/ex42.c.html the Stokes system > > is solved and KSPBuildResidual is used to compute the residuals > > for the velocity components and pressure individually. Are these > > the preconditioned residuals or the true residuals? > > > The true residual. > > > > And how to > > get both? > > > > Precondition it. > > Note that if you only want norms, GMRES will compute one (preconditioned by > default).
Yes, only the norms. As I understand now, GMRES will compute the norm of the total system residual [U,V,W,P], but I would like the norms of [U], [V], [W] and [P] residuals separated. Based on ex42, I got the impression that I have to use KSPBuildResidual. dr. ir. Christiaan Klaij CFD Researcher Research & Development E mailto:C.Klaij at marin.nl T +31 317 49 33 44 MARIN 2, Haagsteeg, P.O. Box 28, 6700 AA Wageningen, The Netherlands T +31 317 49 39 11, F +31 317 49 32 45, I www.marin.nl
