Singular systems come up in solving PDEs almost always due to issues related
to boundary conditions. For example all Neumann (natural) boundary conditions
can produce singular systems. Direct factorizations generically will eventually
hit a zero pivot in such cases and there is no universall
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> *From:* Matthew Knepley
> *Sent:* Monday, March 22, 2021 9:15 AM
> *To:* Sepideh Kavousi
> *Cc:* petsc-users@mcs.anl.gov
> *Subject:* Re: [petsc-users] PF+Navier stokes
>
> On Mon, Mar 22, 2021 at 10:04 AM Sepideh Kavousi wrote:
>
> Hello,
> I want to solve
9:15 AM
To: Sepideh Kavousi
Cc: petsc-users@mcs.anl.gov
Subject: Re: [petsc-users] PF+Navier stokes
On Mon, Mar 22, 2021 at 10:04 AM Sepideh Kavousi
mailto:skav...@lsu.edu>> wrote:
Hello,
I want to solve PF solidification+Navier stokes using Finite different method,
and I have a s
On Mon, Mar 22, 2021 at 10:04 AM Sepideh Kavousi wrote:
> Hello,
> I want to solve PF solidification+Navier stokes using Finite different
> method, and I have a strange problem. My code runs fine for some system
> sizes and fails for some of the system sizes. When I run with the following
> optio
Hello,
I want to solve PF solidification+Navier stokes using Finite different method,
and I have a strange problem. My code runs fine for some system sizes and fails
for some of the system sizes. When I run with the following options:
mpirun -np 2 ./one.out -ts_monitor -snes_fd_color -ts_max_snes
