Hi,
TS_EQ_DAE_SEMI_EXPLICIT_INDEX(?) are defined in TSEquationType but not
mentioned in the manual.
Is this feature functional ?
If yes how do I have to define the RHSFunction?
(I am asking since the ODE variant has it defined as G= M^-1 g, which cannot
work for a DAE)
Best Regards,
Moritz
I believe this is intended to work with most any implicit solver,
*provided* the initial conditions are compatible. It was added by Emil,
but I don't see it explicitly tested in PETSc.
"Huck, Moritz via petsc-users" writes:
> Hi,
> TS_EQ_DAE_SEMI_EXPLICIT_INDEX(?) are defined in TSEquationType
Indeed, various time steppers can take advantage of the differential
form provided and also can serve as a sanity check (e.g., warn users
before they use an explicit solver on an index-2 DAE). To my knowledge,
we do not have solvers that take advantage of semi-explicit DAEs, but
it's good pract
You do not need to worry about these equation flags in the beginning. To solve
a DAE, you need to define IFunction and IJacobian instead of RHSFunction.
ts/examples/tutorials/ex19.c is the simplest DAE example that you can refer to.
Hong (Mr.)
> On Sep 2, 2019, at 4:51 AM, Huck, Moritz via pets
