I only have one field "names vx" and this variable change in both x and y directions. I have also chosen dof in DMDACreate2d to "1".
I am not sure why I should have aF[i][j].vx. "i" defines the grids in x direction and "j" is in y-directions. In all my previous codes I define" aF[j][i].vx" and not "aF[i][j].vx", and it was working properly. Best, Sepideh ________________________________ From: Jed Brown <[email protected]> Sent: Wednesday, February 3, 2021 11:46 AM To: Sepideh Kavousi <[email protected]>; [email protected] <[email protected]> Subject: Re: [petsc-users] SNES-norm is zero all the time Sepideh Kavousi <[email protected]> writes: > I am not running an specific example. Attached is my code. and when I wun > with > ./step5.out -snes_monitor -snes_fd_color -ts_monitor -snes_converged_reason > -pc_type lu > > it seems it does not solve anything because the output is like: > > 0 SNES Function norm 0.000000000000e+00 > Nonlinear solve converged due to CONVERGED_FNORM_ABS iterations 0 > 1 TS dt 0.005 time 0.005 Check your FormFunction for why af[][] is zero. I see aF[j][j].vx but you'll need to set at all the grid points, i.e., aF[j][i].vx and aF[j][i].vy.
