let hybrid vdp mu () = (x, y) where
  rec der x = y init 1.0
  and der y = (mu *. (1.0 -. (x *. x)) *. y) -. x init 1.0

let hybrid sincos () = (sin, cos) where
  rec der sin = cos    init 0.0
  and der cos = -. sin init 1.0

let hybrid both () = (x, y, s, c) where
      (x, y) = vdp 5.0 ()
  and (s, c) = sincos ()

let vdp_d    = Solve.solve_sundials (vdp 5.0)
let sincos_d = Solve.solve_sundials sincos
let both_d   = Solve.solve_sundials both

let main_d = Solve.synchr sincos_d both_d

let node print_vdp (now, (x, y)) =
  print_endline (String.concat ",\t\t" (List.map string_of_float [now;x;y]))

let node print_sincos (now, (s, c)) =
  print_endline (String.concat ",\t\t" (List.map string_of_float [now;s;c]))

let node print_both (now, (x, y, s, c)) =
  print_endline (String.concat ",\t\t" (List.map string_of_float [now;x;y;s;c]))

let node print_main (now, ((s1, c1), (x, y, s2, c2))) =
  print_endline (String.concat ",\t\t" (List.map string_of_float [now;x;y]))

let input _ = ()

let node main () =
  let i = Some (Solve.make(1000.0, input)) fby None in
  let o = run main_d i in
  Solve.period'_t 0.01 print_main o