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Module Float.Array

module Array: sig .. end

Float arrays with packed representation.

type t = floatarray;

The type of float arrays with packed representation.

let length: t => int;

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

let get: (t, int) => float;

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

let set: (t, int, float) => unit;

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

let make: (int, float) => t;

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

let create: int => t;

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

let 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.

let append: (t, t) => t;

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

let concat: list(t) => t;

Same as Float.Array.append, but concatenates a list of floatarrays.

let sub: (t, int, 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.

let copy: t => t;

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

let fill: (t, int, int, float) => unit;

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

let blit: (t, int, t, int, 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.

let to_list: t => list(float);

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

let of_list: list(float) => t;

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

Iterators

let 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); ().

let iteri: ((int, float) => unit, t) => unit;

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

let 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.

let mapi: ((int, float) => float, t) => t;

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

let fold_left: (('a, float) => 'a, '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.

let fold_right: ((float, 'a) => 'a, t, '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

let iter2: ((float, float) => unit, t, t) => unit;

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

let 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)|].

Array scanning

let for_all: (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).

let exists: (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).

let mem: (float, 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.

let mem_ieee: (float, t) => bool;

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

Sorting

let 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, 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
let stable_sort: ((float, float) => int, t) => unit;

Same as Float.Array.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 Float.Array.sort.

let fast_sort: ((float, float) => int, t) => unit;

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

Iterators

let to_seq: t => Seq.t(float);

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

let to_seqi: t => Seq.t((int, float));

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

let of_seq: Seq.t(float) => t;

Create an array from the generator.

let map_to_array: (float => 'a, t) => array('a);

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) |].

let map_from_array: ('a => float, array('a)) => 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.