petsc-3.14.6 2021-03-30

TSSetRHSFunction

Sets the routine for evaluating the function, where U_t = G(t,u).

#include "petscts.h"  
PetscErrorCode  TSSetRHSFunction(TS ts,Vec r,PetscErrorCode (*f)(TS,PetscReal,Vec,Vec,void*),void *ctx)

Logically Collective on TS

	ts	- the TS context obtained from TSCreate()
	r	- vector to put the computed right hand side (or NULL to have it created)
	f	- routine for evaluating the right-hand-side function
	ctx	- [optional] user-defined context for private data for the function evaluation routine (may be NULL)

    PetscErrorCode f(TS ts,PetscReal t,Vec u,Vec F,void *ctx);

	ts	- timestep context
	t	- current timestep
	u	- input vector
	F	- function vector
	ctx	- [optional] user-defined function context

You must call this function or TSSetIFunction() to define your ODE. You cannot use this function when solving a DAE.

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