Re: [petsc-users] Elliptic operator with Neumann conditions

On Wed, Feb 7, 2018 at 2:24 PM, Smith, Barry F. wrote: > >A square matrix with a null space results in an underdetermined system, > that is a solution with more than one solution. The solutions can be > written asx + alpha_1 v_1 + ... alpha_n v_n where the v_n form an

Re: [petsc-users] Elliptic operator with Neumann conditions

PM To: Marco Cisternino Cc: petsc-users Subject: Re: [petsc-users] Elliptic operator with Neumann conditions A square matrix with a null space results in an underdetermined system, that is a solution with more than one solution. The solutions can be written asx + alpha_1 v_1 + ... alpha

Re: [petsc-users] Elliptic operator with Neumann conditions

A square matrix with a null space results in an underdetermined system, that is a solution with more than one solution. The solutions can be written asx + alpha_1 v_1 + ... alpha_n v_n where the v_n form an orthonormal basis for the null space and x is orthogonal to the null space.

Re: [petsc-users] Elliptic operator with Neumann conditions

t; > Da: Matthew Knepley <knep...@gmail.com> > Inviato: mercoledì 7 febbraio 2018 19:38:08 > A: Marco Cisternino > Cc: petsc-users > Oggetto: Re: [petsc-users] Elliptic operator with Neumann conditions > > On Thu, Feb 8, 20

Re: [petsc-users] Elliptic operator with Neumann conditions

Collegno 18, Torino, Italia. +3901119719782 www.optimad.it Da: Matthew Knepley <knep...@gmail.com> Inviato: mercoledì 7 febbraio 2018 19:38:08 A: Marco Cisternino Cc: petsc-users Oggetto: Re: [petsc-users] Elliptic operator with Neumann conditions On Th

Re: [petsc-users] Elliptic operator with Neumann conditions

no, Italia. > +3901119719782 > www.optimad.it > > > > Da: Matthew Knepley <knep...@gmail.com> > Inviato: mercoledì 7 febbraio 2018 18:57:56 > A: Marco Cisternino > Cc: petsc-users > Oggetto: Re: [petsc-users] Elliptic operator with Neumann conditions >

Re: [petsc-users] Elliptic operator with Neumann conditions

. +3901119719782 www.optimad.it Da: Matthew Knepley <knep...@gmail.com> Inviato: mercoledì 7 febbraio 2018 18:57:56 A: Marco Cisternino Cc: petsc-users Oggetto: Re: [petsc-users] Elliptic operator with Neumann conditions On Thu, Feb 8, 2018 at 4:43 AM,

Re: [petsc-users] Elliptic operator with Neumann conditions

On Thu, Feb 8, 2018 at 4:43 AM, Marco Cisternino < marco.cistern...@optimad.it> wrote: > Hi everybody, > I would like to ask what solution is computed if I try to solve the linear > system relative to the problem in subject without creating the null space. > I tried with and without the call to >