You are in a very lucky position in terms of debugging because you have a running code you can compare with, take advantage of this fact.
Ok, you're going to have to see when the two codes start diverging from each other. First run with -ts_monitor -snes_monitor -ksp_monitor Do the initial values for the monitor match, or do no values match? Put at VecView in both codes on your initial value for x (the initial conditions for the ODE) are they the same? Next you should put a VecView() at the end of your IFunction routine and a MatView at the end of your IJacobian routine to make sure they are producing the same values. Good luck Barry > On Apr 1, 2019, at 10:28 AM, Nicola Creati via petsc-users > <[email protected]> wrote: > > The Python and C solutions are different. I used the following commands: > > Python: python ex13.py -ts_max_step 5 -pc_type lu > > C: ./ex13 -ts_max_step 5 -pc_type lu > > I attached the two solutions, values and distributions are different. > > Thanks. > > Nicola > > -- > > Nicola Creati > Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS > www.inogs.it > Dipartimento di Geofisica della Litosfera Geophysics of Lithosphere Department > CARS (Cartography and Remote Sensing) Research Group http://www.inogs.it/Cars/ > Borgo Grotta Gigante 42/c 34010 Sgonico - Trieste - ITALY > [email protected] > off. +39 040 2140 213 > fax. +39 040 327307 > > _____________________________________________________________________ > This communication, that may contain confidential and/or legally privileged > information, is intended solely for the use of the intended addressees. > Opinions, conclusions and other information contained in this message, that > do not relate to the official business of OGS, shall be considered as not > given or endorsed by it. Every opinion or advice contained in this > communication is subject to the terms and conditions provided by the > agreement governing the engagement with such a client. Any use, disclosure, > copying or distribution of the contents of this communication by a > not-intended recipient or in violation of the purposes of this communication > is strictly prohibited and may be unlawful. For Italy only: Ai sensi del > D.Lgs.196/2003 - "T.U. sulla Privacy" si precisa che le informazioni > contenute in questo messaggio sono riservate ed a uso esclusivo del > destinatario. > > <python_sol.png><c_sol.png>
