[petsc-users] Problem in using TS objects

[Jed Brown]

Yingjie Wu <yjwu16 at gmail.com> writes:

> Hi Jed,
> Thank you very much for your detailed answer. It helps me a lot.
> I'm going to use the "chain rule" method to solve my problem first, and may
> continue to try different ways later.
> For your reply, I have the following questions:
>   1. The method of transforming equations into DAE, for my problem, does it
> mean taking \ rho as a variable and adding its constitutive equation as a
> residual equation?
>   f(\rho) = \rho - subroutine_compute_rho(P,E)

Yes.

>   2. I hope to use finite difference to construct Jacobian matrix
> first(this means that I may not provide the IJacobian function). Is the
> previous switch "-snes_fd" still available for transient   calculation?

Yes.

>   3. For the new merge request you have mentioned, where should I get the
> information so as to get its new developments?

You can enable notifications for this issue (see right sidebar) to get
updates on my forthcoming MR.

https://gitlab.com/petsc/petsc/issues/547