On Thu, Sep 8, 2011 at 14:58, Tian(ICT) <rongtian at ncic.ac.cn> wrote:
> By 50 iterations, I meant my implementation of this prescribed boundary > condition was not working, > not converging. Yes, I put 1 on the diagonal.\ > Is the system singular? What equations are you solving? Do boundary conditions give you a constant null space? Incompressible flow is this way. Run with -ksp_monitor_true_residual -pc_type lu -snes_view and send the output. > Can I just enforce the solution x within each Newton iteration to the > prescribed values to satisfy the prescribed boundary condition, not > MatZeroRowsing Jacobian? > It's important for the linear system to be nonsingular. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20110908/987c3829/attachment.htm>
