(** Module: Signal Description: signal definition and operations. @author WANG Haisheng Created: 03/06/2013 Modified: 03/06/2013 *) open Types;; open Basic;; open Value;; exception Signal_operation of string;; let delay_memory_length = 10000;; class signal : int -> (time -> value_type) -> signal_type = fun (freq_init : int) -> fun (func_init : time -> value_type) -> object (self) val mutable signal_func = func_init val mutable memory_length = 0 method frequency = freq_init method at = signal_func method private check_freq : signal_type list -> int = fun (sl : signal_type list) -> let check : int -> signal_type -> int = fun (f : int) -> fun (s : signal_type) -> if f = s#frequency || s#frequency = 0 then f else if f = 0 then s#frequency else raise (Signal_operation "frequency not matched.") in List.fold_left check self#frequency sl method private add_memory : int -> unit = fun (length : int) -> assert (length >= 0); if memory_length >= length then () else let memory = Hashtbl.create length in let func : time -> value = fun (t : time) -> try Hashtbl.find memory t with Not_found -> let result = func_init t in let () = Hashtbl.replace memory t result in let () = if (t - length) >= 0 then Hashtbl.remove memory (t - length) else () in result in memory_length <- length; signal_func <- func method private delay_by : int -> time -> value = fun i -> fun t -> if (t - i) >= 0 then self#at (t - i) else if t >= 0 && (t - i) < 0 then (self#at 0)#zero else raise (Signal_operation "Delay time < 0.") method private prim1 : (time -> value_type) -> signal_type = fun (func : time -> value_type) -> let freq = self#frequency in new signal freq func method private prim2 : (time -> value_type -> value_type) -> signal_type -> signal_type = fun (func_binary : time -> value_type -> value_type) -> fun (s : signal_type) -> let freq = self#check_freq [s] in let func = fun t -> (func_binary t) (s#at t) in new signal freq func method neg = self#prim1 (fun t -> (self#at t)#neg) method floor = self#prim1 (fun t -> (self#at t)#floor) method sin = self#prim1 (fun t -> (self#at t)#sin) method cos = self#prim1 (fun t -> (self#at t)#cos) method atan = self#prim1 (fun t -> (self#at t)#atan) method sqrt = self#prim1 (fun t -> (self#at t)#sqrt) method int = self#prim1 (fun t -> (self#at t)#int) method add = self#prim2 (fun t -> (self#at t)#add) method sub = self#prim2 (fun t -> (self#at t)#sub) method mul = self#prim2 (fun t -> (self#at t)#mul) method div = self#prim2 (fun t -> (self#at t)#div) method atan2 = self#prim2 (fun t -> (self#at t)#atan2) method _mod = self#prim2 (fun t -> (self#at t)#_mod) method larger = self#prim2 (fun t -> (self#at t)#larger) method smaller = self#prim2 (fun t -> (self#at t)#smaller) method delay : signal_type -> signal_type = fun (s : signal_type) -> let freq = self#check_freq [s] in let () = self#add_memory delay_memory_length in let func : time -> value_type = fun (t : time) -> let i = (s#at t)#to_int in self#delay_by t i in new signal freq func method mem : signal_type = let freq = self#frequency in let () = self#add_memory 1 in let func = fun (t : time) -> self#delay_by t 1 in new signal freq func method rdtable : signal_type -> signal_type -> signal_type = fun (s_size : signal_type) -> fun (s_index : signal_type) -> let freq = self#check_freq [s_index] in let () = self#add_memory ((s_size#at 0)#to_int) in let func : time -> value_type = fun t -> self#at ((s_index#at t)#to_int) in new signal freq func method select2 : signal_type -> signal_type -> signal_type = fun s_first -> fun s_second -> let freq = self#check_freq [s_first; s_second] in let func : time -> value_type = fun t -> let i = (self#at t)#to_int in if i = 0 then s_first#at t else if i = 1 then s_second#at t else raise (Signal_operation "select2 index 0|1.") in new signal freq func method select3 : signal_type -> signal_type -> signal_type -> signal_type = fun s_first -> fun s_second -> fun s_third -> let freq = self#check_freq [s_first; s_second; s_third] in let func : time -> value_type = fun t -> let i = (self#at t)#to_int in if i = 0 then s_first#at t else if i = 1 then s_second#at t else if i = 2 then s_third#at t else raise (Signal_operation "select2 index 0|1.") in new signal freq func method prefix : signal_type -> signal_type = fun (s_init : signal_type) -> let func : time -> value_type = fun t -> if t = 0 then s_init#at 0 else if t > 0 then self#at t else raise (Signal_operation "prefix time < 0.") in new signal self#frequency func method vectorize : signal_type -> signal_type = fun s_size -> let size = (s_size#at 0)#to_int in if size <= 0 then raise (Signal_operation "Vectorize: size <= 0.") else let freq = self#frequency / size in let func : time -> value_type = fun t -> let vec = fun i -> (self#at (size * t + i))#get in new value (Vec (new vector size vec)) in new signal freq func method serialize : signal_type = let size = match (self#at 0)#get with | Vec vec -> vec#size | _ -> raise (Signal_operation "Serialize: scalar input.") in let freq = self#frequency * size in let func : time -> value_type = fun t -> match (self#at (t/size))#get with | Vec vec -> new value (vec#nth (t mod size)) | _ -> raise (Signal_operation "Serialize: signal type not consistent.") in new signal freq func method vconcat : signal_type -> signal_type = fun s -> let freq = self#check_freq [s] in let func : time -> value_type = fun t -> match ((self#at t)#get, (s#at t)#get) with | (Vec vec1, Vec vec2) -> let size1 = vec1#size in let size2 = vec2#size in let size = size1 + size2 in let vec = fun i -> if i < size1 then vec1#nth i else vec2#nth (i - size1) in new value (Vec (new vector size vec)) | _ -> raise (Signal_operation "Vconcat: scalar.") in new signal freq func method vpick : signal_type -> signal_type = fun s_index -> let freq = self#check_freq [s_index] in let func : time -> value_type = fun t -> let i = (s_index#at t)#to_int in match (self#at t)#get with | Vec vec -> new value (vec#nth i) | _ -> raise (Signal_operation "Vpick: scalar.") in new signal freq func end;;