[petsc-users] about FD Jacobian for the new DAE solver

Li, Zhisong (lizs) lizs at mail.uc.edu
Thu Apr 29 16:08:38 CDT 2010


Last time I was suggested by Jed using the DAE solver to build my nonlinear CFD code based on TS. For incompressible N-S equations, I think it's difficult to derive the analytical Jacobian formulation, and we need a finite difference approximation or matrix-free method.

What I previously done was integrating the incompressible N-S equations into tutorial code ts/ex7.c  . It simply uses an argument "TSDefaultComputeJacobianColor" to finish the Jacobian issue. When I switch to TSSetIFunction() and TSSetIJacobian(), this argument doesn't work anymore. And if I remove all Jacobian-related lines and use -snes_mf command option, it prompts out error message "Must Set Jacobian!". Do you know how to resolve this for both methods?

Thank you.


Zhisong Li
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20100429/9ca0bccf/attachment.htm>

More information about the petsc-users mailing list