> 1) Are you sure the -vecscatter_reproduce is working, run with - > options_left and see if > says the option was not used.
I have harwired it into the 2.3.3-p8, following your suggestion. > 2) did you do the -ksp_rtol 1.e-12 at the same time as the - > vecscatter_reproduce? They > must be done together. No, I tested the two separately. I will do as you suggest. > 3) what happens on 1 process? Does it behave exactly the same for two > identical runs? The current testcase is too large to be run on a single processor. Tests performed with smaller datasets (both 2 and 3D) have shown that on 1 proc subsequent runs produce identical output. It should also be mentioned that, on a different grid (somewhat less stretched) the same testcase produces far more repeatible non-linear convergence histories. By "far more repeatible" I mean that the output of subsequent runs are NOT identical, but the non-linear convergence histories are almost superimposed at the "plotting" level, small differences arising only when the residuals are close to machine eps. On this grid, the linear solver (either BJ+ILU(k) or ASM+ILU(k)) also behaves far better. > 4) there is too much going on here to figure out why you get this > behavior. Can you please > FIX the continuation parameter Here I am not sure about the nomenclature: by "continuation parameter" do you mean the strategy by which the pseudo-time derivative term is progressively reduced so as to revert to a true Newton algorithm? My pseudo-time derivative term looks like 1/(CFL) * (Volume/dt) Volume/dt is locally computed based on an explicit stability criterion and CFL is ramped from a starting value (CFL_0, tipically of order 1 or 10) using the ratio between the current and initial residuals of one of the conservation eqns (mass, tipically). In all previous plots, the fixed point iterations were not shown. The fixed point iteration was run only once to generate the initial solution used for all Newton runs. Aldo -- Dr. Aldo Bonfiglioli Dip.to di Ingegneria e Fisica dell'Ambiente (DIFA) Universita' della Basilicata V.le dell'Ateneo lucano, 10 85100 Potenza ITALY tel:+39.0971.205203 fax:+39.0971.205160
