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 petsc-users > <[email protected]> wrote: > > 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
