Module `Float.Array`

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.

Raise Invalid_argument if n is outside the range 0 to (length a - 1).

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

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

Raise Invalid_argument if n is outside the range 0 to (length a - 1).

val make : int -> float -> t

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

Raise Invalid_argument if n < 0 or n > Sys.max_floatarray_length.

val create : int -> t

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

Raise Invalid_argument if n < 0 or n > Sys.max_floatarray_length.

val init : int -> (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.

Raise Invalid_argument if n < 0 or n > Sys.max_floatarray_length.

val append : t -> t -> t

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

Raise Invalid_argument if length v1 + length v2 > Sys.max_floatarray_length.

val concat : t list -> t: Same as append, but concatenates a list of floatarrays.

val sub : t -> int -> int -> t

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

Raise Invalid_argument if start and len do not designate a valid subarray of a; that is, if start < 0, or len < 0, or start + 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 -> int -> int -> float -> unit

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

Raise Invalid_argument if ofs and len do not designate a valid subarray of a.

val blit : t -> int -> t -> int -> int -> unit

blit v1 o1 v2 o2 len copies len elements from floatarray v1, starting at element number o1, to floatarray v2, starting at element number o2. It works correctly even if v1 and v2 are the same floatarray, and the source and destination chunks overlap.

Raise Invalid_argument if o1 and len do not designate a valid subarray of v1, or if o2 and len do not designate a valid subarray of v2.

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.

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

Iterators

val iter : (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 : (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 : (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 : (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 : ('a -> float -> 'a) -> 'a -> t -> 'a: fold_left f x a computes f (... (f (f x a.(0)) a.(1)) ...) a.(n-1), where n is the length of the floatarray a.

val fold_right : (float -> 'a -> 'a) -> t -> 'a -> 'a: fold_right f a x computes f a.(0) (f a.(1) ( ... (f a.(n-1) x) ...)), where n is the length of the floatarray a.

Iterators on two arrays

val iter2 : (float -> float -> unit) -> t -> t -> unit: Array.iter2 f a b applies function f to all the elements of a and b. Raise Invalid_argument if the floatarrays are not the same size.

val map2 : (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)|]. Raise Invalid_argument if the floatarrays are not the same size.

Array scanning

val for_all : (float -> bool) -> t -> bool: for_all p [|a1; ...; an|] checks if all elements of the floatarray satisfy the predicate p. That is, it returns (p a1) && (p a2) && ... && (p an).

val exists : (float -> bool) -> t -> bool: exists p [|a1; ...; an|] checks if at least one element of the floatarray satisfies the predicate p. That is, it returns (p a1) || (p a2) || ... || (p an).

val mem : float -> t -> bool: mem a l is true if and only if there is an element of l that is structurally equal to a, i.e. there is an x in l such that compare a x = 0.

val mem_ieee : float -> t -> bool: Same as mem, but uses IEEE equality instead of structural equality.

Sorting

val sort : (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 : (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 : (float -> float -> int) -> t -> unit: Same as sort or stable_sort, whichever is faster on typical input.

Iterators

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 iterator.

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 iterator.

val of_seq : float Seq.t -> t: Create an array from the generator.

val map_to_array : (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 : ('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.

Undocumented functions

val unsafe_get : t -> int -> float
val unsafe_set : t -> int -> float -> unit