ocaml-containers/src/core/CCFloat.ml
Raphael Sousa Santos 4936cb60d4 Add CCFloat.pi
2020-05-15 14:27:59 -05:00

127 lines
2.8 KiB
OCaml

(* This file is free software, part of containers. See file "license" for more details. *)
open CCShims_
type t = float
type fpclass = Stdlib.fpclass =
| FP_normal
| FP_subnormal
| FP_zero
| FP_infinite
| FP_nan
module Infix = struct
let (=) : t -> t -> bool = Stdlib.(=)
let (<>) : t -> t -> bool = Stdlib.(<>)
let (<) : t -> t -> bool = Stdlib.(<)
let (>) : t -> t -> bool = Stdlib.(>)
let (<=) : t -> t -> bool = Stdlib.(<=)
let (>=) : t -> t -> bool = Stdlib.(>=)
let (~-) : t -> t = Stdlib.(~-.)
let (+) : t -> t -> t = Stdlib.(+.)
let (-) : t -> t -> t = Stdlib.(-.)
let ( * ) : t -> t -> t = Stdlib.( *. )
let (/) : t -> t -> t = Stdlib.(/.)
end
include Infix
let nan = Stdlib.nan
let infinity = Stdlib.infinity
let neg_infinity = Stdlib.neg_infinity
let max_value = infinity
let min_value = neg_infinity
let max_finite_value = Stdlib.max_float
let epsilon = Stdlib.epsilon_float
let pi = 0x1.921fb54442d18p+1
let is_nan x = Stdlib.(classify_float x = Stdlib.FP_nan)
let add = (+.)
let sub = (-.)
let mul = ( *. )
let div = (/.)
let neg = (~-.)
let abs = Stdlib.abs_float
let scale = ( *. )
let min (x : t) y =
match Stdlib.classify_float x, Stdlib.classify_float y with
| FP_nan, _ -> y
| _, FP_nan -> x
| _ -> if x < y then x else y
let max (x : t) y =
match Stdlib.classify_float x, Stdlib.classify_float y with
| FP_nan, _ -> y
| _, FP_nan -> x
| _ -> if x > y then x else y
(*$T
max nan 1. = 1.
min nan 1. = 1.
max 1. nan = 1.
min 1. nan = 1.
*)
(*$Q
Q.(pair float float) (fun (x,y) -> \
is_nan x || is_nan y || (min x y <= x && min x y <= y))
Q.(pair float float) (fun (x,y) -> \
is_nan x || is_nan y || (max x y >= x && max x y >= y))
*)
let equal (a:float) b = a=b
let hash : t -> int = Hashtbl.hash
let compare (a:float) b = Stdlib.compare a b
type 'a printer = Format.formatter -> 'a -> unit
type 'a random_gen = Random.State.t -> 'a
let pp = Format.pp_print_float
let fsign a =
if is_nan a then nan
else if a = 0. then a
else Stdlib.copysign 1. a
exception TrapNaN of string
let sign_exn (a:float) =
if is_nan a then raise (TrapNaN "sign_exn")
else compare a 0.
let round x =
let low = floor x in
let high = ceil x in
if x-.low > high-.x then high else low
(*$=
2. (round 1.6)
1. (round 1.4)
0. (round 0.)
*)
let to_int (a:float) = Stdlib.int_of_float a
let of_int (a:int) = Stdlib.float_of_int a
let to_string (a:float) = Stdlib.string_of_float a
let of_string_exn (a:string) = Stdlib.float_of_string a
let of_string_opt (a:string) =
try Some (Stdlib.float_of_string a)
with Failure _ -> None
let random n st = Random.State.float st n
let random_small = random 100.0
let random_range i j st = i +. random (j-.i) st
let equal_precision ~epsilon a b = abs_float (a-.b) < epsilon
let classify = Stdlib.classify_float