On Mon, Dec 12, 2016 at 1:04 AM, Matthew Knepley <[email protected]> wrote:
> On Mon, Dec 12, 2016 at 12:56 AM, Praveen C <[email protected]> wrote: > >> Increasing number of snes iterations, I get convergence. >> >> So it is a problem of initial guess being too far from the solution of >> the nonlinear equation. >> >> Solution can be seen here >> >> https://github.com/cpraveen/fenics/blob/master/1d/cosmic_ray >> /cosmic_ray.ipynb >> > Also, how is this a parabolic equation? It looks like u/|u'| to me, which does not look parabolic at all. Matt > Green curve is solution after two time steps. >> >> It took about 100 snes iterations in first time step and about 50 in >> second time step. >> >> I use exact Jacobian and direct LU solve. >> > > I do not believe its the correct Jacobian. Did you test it as I asked? > Also run with > > -snes_monitor -ksp_monitor_true_residual -snes_view > -snes_converged_reason > > and then > > -snes_fd > > and send all the output > > Matt > > >> Thanks >> praveen >> > > > > -- > What most experimenters take for granted before they begin their > experiments is infinitely more interesting than any results to which their > experiments lead. > -- Norbert Wiener > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener
