15 int evolver_rk(
int (*derivs)(
double x,
18 void * parameters_and_workspace,
19 ErrorMsg error_message),
25 void * parameters_and_workspace_for_derivs,
27 double minimum_variation,
28 int (*evaluate_timescale)(
double x,
29 void * parameters_and_workspace,
31 ErrorMsg error_message),
32 double timestep_over_timescale,
39 void * parameters_and_workspace,
40 ErrorMsg error_message),
41 int (*print_variables)(
double x,
44 void * parameters_and_workspace,
45 ErrorMsg error_message),
46 ErrorMsg error_message);