Module Float.ArrayLabels

Float arrays with packed representation (labeled functions).

type t = floatarray

The type of float arrays with packed representation.

  • since 4.08.0
val length : t -> int

Return the length (number of elements) of the given floatarray.

val get : t -> int -> float

get a n returns the element number n of floatarray a.

val set : t -> int -> float -> unit

set a n x modifies floatarray a in place, replacing element number n with x.

val make : int -> float -> t

make n x returns a fresh floatarray of length n, initialized with x.

val create : int -> t

create n returns a fresh floatarray of length n, with uninitialized data.

val init : int -> f:(int -> float) -> t

init n ~f returns a fresh floatarray of length n, with element number i initialized to the result of f i. In other terms, init n ~f tabulates the results of f applied to the integers 0 to n-1.

val append : t -> t -> t

append v1 v2 returns a fresh floatarray containing the concatenation of the floatarrays v1 and v2.

val concat : t list -> t

Same as append, but concatenates a list of floatarrays.

val sub : t -> pos:int -> len:int -> t

sub a ~pos ~len returns a fresh floatarray of length len, containing the elements number pos to pos + len - 1 of floatarray a.

  • raises Invalid_argument

    if pos and len do not designate a valid subarray of a; that is, if pos < 0, or len < 0, or pos + len > length a.

val copy : t -> t

copy a returns a copy of a, that is, a fresh floatarray containing the same elements as a.

val fill : t -> pos:int -> len:int -> float -> unit

fill a ~pos ~len x modifies the floatarray a in place, storing x in elements number pos to pos + len - 1.

val blit : src:t -> src_pos:int -> dst:t -> dst_pos:int -> len:int -> unit

blit ~src ~src_pos ~dst ~dst_pos ~len copies len elements from floatarray src, starting at element number src_pos, to floatarray dst, starting at element number dst_pos. It works correctly even if src and dst are the same floatarray, and the source and destination chunks overlap.

  • raises Invalid_argument

    if src_pos and len do not designate a valid subarray of src, or if dst_pos and len do not designate a valid subarray of dst.

val to_list : t -> float list

to_list a returns the list of all the elements of a.

val of_list : float list -> t

of_list l returns a fresh floatarray containing the elements of l.

  • raises Invalid_argument

    if the length of l is greater than Sys.max_floatarray_length.

Iterators

val iter : f:(float -> unit) -> t -> unit

iter ~f a applies function f in turn to all the elements of a. It is equivalent to f a.(0); f a.(1); ...; f a.(length a - 1); ().

val iteri : f:(int -> float -> unit) -> t -> unit

Same as iter, but the function is applied with the index of the element as first argument, and the element itself as second argument.

val map : f:(float -> float) -> t -> t

map ~f a applies function f to all the elements of a, and builds a floatarray with the results returned by f.

val mapi : f:(int -> float -> float) -> t -> t

Same as map, but the function is applied to the index of the element as first argument, and the element itself as second argument.

val fold_left : f:('a -> float -> 'a) -> init:'a -> t -> 'a

fold_left ~f x ~init computes f (... (f (f x init.(0)) init.(1)) ...) init.(n-1), where n is the length of the floatarray init.

val fold_right : f:(float -> 'a -> 'a) -> t -> init:'a -> 'a

fold_right f a init computes f a.(0) (f a.(1) ( ... (f a.(n-1) init) ...)), where n is the length of the floatarray a.

Iterators on two arrays

val iter2 : f:(float -> float -> unit) -> t -> t -> unit

Array.iter2 ~f a b applies function f to all the elements of a and b.

val map2 : f:(float -> float -> float) -> t -> t -> t

map2 ~f a b applies function f to all the elements of a and b, and builds a floatarray with the results returned by f: [| f a.(0) b.(0); ...; f a.(length a - 1) b.(length b - 1)|].

Array scanning

val for_all : f:(float -> bool) -> t -> bool

for_all ~f [|a1; ...; an|] checks if all elements of the floatarray satisfy the predicate f. That is, it returns (f a1) && (f a2) && ... && (f an).

val exists : f:(float -> bool) -> t -> bool

exists f [|a1; ...; an|] checks if at least one element of the floatarray satisfies the predicate f. That is, it returns (f a1) || (f a2) || ... || (f an).

val mem : float -> set:t -> bool

mem a ~set is true if and only if there is an element of set that is structurally equal to a, i.e. there is an x in set such that compare a x = 0.

val mem_ieee : float -> set:t -> bool

Same as mem, but uses IEEE equality instead of structural equality.

Sorting

val sort : cmp:(float -> float -> int) -> t -> unit

Sort a floatarray in increasing order according to a comparison function. The comparison function must return 0 if its arguments compare as equal, a positive integer if the first is greater, and a negative integer if the first is smaller (see below for a complete specification). For example, Stdlib.compare is a suitable comparison function. After calling sort, the array is sorted in place in increasing order. sort is guaranteed to run in constant heap space and (at most) logarithmic stack space.

The current implementation uses Heap Sort. It runs in constant stack space.

Specification of the comparison function: Let a be the floatarray and cmp the comparison function. The following must be true for all x, y, z in a :

  • cmp x y > 0 if and only if cmp y x < 0
  • if cmp x y >= 0 and cmp y z >= 0 then cmp x z >= 0

When sort returns, a contains the same elements as before, reordered in such a way that for all i and j valid indices of a :

  • cmp a.(i) a.(j) >= 0 if and only if i >= j
val stable_sort : cmp:(float -> float -> int) -> t -> unit

Same as sort, but the sorting algorithm is stable (i.e. elements that compare equal are kept in their original order) and not guaranteed to run in constant heap space.

The current implementation uses Merge Sort. It uses a temporary floatarray of length n/2, where n is the length of the floatarray. It is usually faster than the current implementation of sort.

val fast_sort : cmp:(float -> float -> int) -> t -> unit

Same as sort or stable_sort, whichever is faster on typical input.

Float arrays and Sequences

val to_seq : t -> float Seq.t

Iterate on the floatarray, in increasing order. Modifications of the floatarray during iteration will be reflected in the sequence.

val to_seqi : t -> (int * float) Seq.t

Iterate on the floatarray, in increasing order, yielding indices along elements. Modifications of the floatarray during iteration will be reflected in the sequence.

val of_seq : float Seq.t -> t

Create an array from the generator.

val map_to_array : f:(float -> 'a) -> t -> 'a array

map_to_array ~f a applies function f to all the elements of a, and builds an array with the results returned by f: [| f a.(0); f a.(1); ...; f a.(length a - 1) |].

val map_from_array : f:('a -> float) -> 'a array -> t

map_from_array ~f a applies function f to all the elements of a, and builds a floatarray with the results returned by f.