Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread Eric Chamberland via petsc-users
). I do this in SNES ex62 and ex69, and other examples.   Thanks,      Matt Thanks, Pierre Regards, Nicolas *De :*pierre.joli...@lip6.fr *Envoyé :*mercredi 12 juillet 2023 19:52 *À :*TARDIEU Nicolas *Cc :*petsc-us

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread Stefano Zampini
ly, I hated this as well, so I built a way around it _if_ you are >>> using a DM to define the problem. Then >>> you can set a "nullspace constructor" to make it if the field you are >>> talking about is ever extracted. You use DMSetNullSpaceConstructor(). I do &

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread Stefano Zampini
s in SNES ex62 and ex69, and other examples. >> >> Thanks, >> >> Matt >> >> >>> Thanks, >>> Pierre >>> >>> Regards, >>> Nicolas >>> >>> -- >>> *De :* pierre.j

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread Karin
his in SNES ex62 and ex69, and other examples. > > Thanks, > > Matt > > >> Thanks, >> Pierre >> >> Regards, >> Nicolas >> >> -- >> *De :* pierre.joli...@lip6.fr >> *Envoyé :* mercredi 12 juillet 2023 1

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread Matthew Knepley
onstructor(). I do this in SNES ex62 and ex69, and other examples. Thanks, Matt > Thanks, > Pierre > > Regards, > Nicolas > > -- > *De :* pierre.joli...@lip6.fr > *Envoyé :* mercredi 12 juillet 2023 19:52 > *À :* TARDIEU Nicolas &g

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread Pierre Jolivet
re.joli...@lip6.fr > Envoyé : mercredi 12 juillet 2023 19:52 > À : TARDIEU Nicolas > Cc : petsc-users@mcs.anl.gov > Objet : Re: [petsc-users] Near null space for a fieldsplit in petsc4py > > > > On 12 Jul 2023, at 6:04 PM, TARDIEU Nicolas via petsc-users > > wro

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-13 Thread TARDIEU Nicolas via petsc-users
operator's MatNest and then append the null space to it. Anyway this is a bit tricky... Regards, Nicolas De : pierre.joli...@lip6.fr Envoyé : mercredi 12 juillet 2023 19:52 À : TARDIEU Nicolas Cc : petsc-users@mcs.anl.gov Objet : Re: [petsc-users] Near null space

Re: [petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-12 Thread Pierre Jolivet
> On 12 Jul 2023, at 6:04 PM, TARDIEU Nicolas via petsc-users > wrote: > > Dear PETSc team, > > In the attached example, I set up a block pc for a saddle-point problem in > petsc4py. The IS define the unknowns, namely some physical quantity (phys) > and a Lagrange multiplier (lags). > I

[petsc-users] Near null space for a fieldsplit in petsc4py

2023-07-12 Thread TARDIEU Nicolas via petsc-users
Dear PETSc team, In the attached example, I set up a block pc for a saddle-point problem in petsc4py. The IS define the unknowns, namely some physical quantity (phys) and a Lagrange multiplier (lags). I would like to attach a near null space to the physical block, in order to get the best