Hello I am trying to solve system of equations using time stepping. I use TSSetIFunction() to define the DAEs. I tried to add the xdot[] term to all of variables. As a solution algorithm , I solved with newton line search with ASM as a preconditioner. In the case, I want to add the xdot[] term to only one term, energy equation, I got PCSETUP_FAILED due to FACTOR_NUMERIC_ZEROPIVOT and failed to solve. Do you know how I can deal with this? So Sorry for may be confusing you with my explanation! If you need more information of my case, let me know. Thanks for your time answering.
Thanks Amir
