Provided by: ocaml-nox_4.01.0-3ubuntu3.1_amd64 
NAME
Bigarray - Large, multi-dimensional, numerical arrays.
Module
Module Bigarray
Documentation
Module Bigarray
: sig end
Large, multi-dimensional, numerical arrays.
This module implements multi-dimensional arrays of integers and floating-point numbers, thereafter
referred to as 'big arrays'. The implementation allows efficient sharing of large numerical arrays
between OCaml code and C or Fortran numerical libraries.
Concerning the naming conventions, users of this module are encouraged to do open Bigarray in their
source, then refer to array types and operations via short dot notation, e.g. Array1.t or Array2.sub .
Big arrays support all the OCaml ad-hoc polymorphic operations:
-comparisons ( = , <> , <= , etc, as well as Pervasives.compare );
-hashing (module Hash );
-and structured input-output (the functions from the Marshal module, as well as Pervasives.output_value
and Pervasives.input_value ).
=== Element kinds ===
=== Big arrays can contain elements of the following kinds: - IEEE single precision (32 bits)
floating-point numbers (Bigarray.float32_elt), - IEEE double precision (64 bits) floating-point numbers
(Bigarray.float64_elt), - IEEE single precision (2 * 32 bits) floating-point complex numbers
(Bigarray.complex32_elt), - IEEE double precision (2 * 64 bits) floating-point complex numbers
(Bigarray.complex64_elt), - 8-bit integers (signed or unsigned) (Bigarray.int8_signed_elt or
Bigarray.int8_unsigned_elt), - 16-bit integers (signed or unsigned) (Bigarray.int16_signed_elt or
Bigarray.int16_unsigned_elt), - OCaml integers (signed, 31 bits on 32-bit architectures, 63 bits on
64-bit architectures) (Bigarray.int_elt), - 32-bit signed integer (Bigarray.int32_elt), - 64-bit signed
integers (Bigarray.int64_elt), - platform-native signed integers (32 bits on 32-bit architectures, 64
bits on 64-bit architectures) (Bigarray.nativeint_elt). Each element kind is represented at the type
level by one of the abstract types defined below. ===
type float32_elt
type float64_elt
type complex32_elt
type complex64_elt
type int8_signed_elt
type int8_unsigned_elt
type int16_signed_elt
type int16_unsigned_elt
type int_elt
type int32_elt
type int64_elt
type nativeint_elt
type ('a, 'b) kind
To each element kind is associated an OCaml type, which is the type of OCaml values that can be stored in
the big array or read back from it. This type is not necessarily the same as the type of the array
elements proper: for instance, a big array whose elements are of kind float32_elt contains 32-bit single
precision floats, but reading or writing one of its elements from OCaml uses the OCaml type float , which
is 64-bit double precision floats.
The abstract type ('a, 'b) kind captures this association of an OCaml type 'a for values read or written
in the big array, and of an element kind 'b which represents the actual contents of the big array. The
following predefined values of type kind list all possible associations of OCaml types with element
kinds:
val float32 : (float, float32_elt) kind
See Bigarray.char .
val float64 : (float, float64_elt) kind
See Bigarray.char .
val complex32 : (Complex.t, complex32_elt) kind
See Bigarray.char .
val complex64 : (Complex.t, complex64_elt) kind
See Bigarray.char .
val int8_signed : (int, int8_signed_elt) kind
See Bigarray.char .
val int8_unsigned : (int, int8_unsigned_elt) kind
See Bigarray.char .
val int16_signed : (int, int16_signed_elt) kind
See Bigarray.char .
val int16_unsigned : (int, int16_unsigned_elt) kind
See Bigarray.char .
val int : (int, int_elt) kind
See Bigarray.char .
val int32 : (int32, int32_elt) kind
See Bigarray.char .
val int64 : (int64, int64_elt) kind
See Bigarray.char .
val nativeint : (nativeint, nativeint_elt) kind
See Bigarray.char .
val char : (char, int8_unsigned_elt) kind
As shown by the types of the values above, big arrays of kind float32_elt and float64_elt are accessed
using the OCaml type float . Big arrays of complex kinds complex32_elt , complex64_elt are accessed with
the OCaml type Complex.t . Big arrays of integer kinds are accessed using the smallest OCaml integer
type large enough to represent the array elements: int for 8- and 16-bit integer bigarrays, as well as
OCaml-integer bigarrays; int32 for 32-bit integer bigarrays; int64 for 64-bit integer bigarrays; and
nativeint for platform-native integer bigarrays. Finally, big arrays of kind int8_unsigned_elt can also
be accessed as arrays of characters instead of arrays of small integers, by using the kind value char
instead of int8_unsigned .
=== Array layouts ===
type c_layout
See Bigarray.fortran_layout .
type fortran_layout
To facilitate interoperability with existing C and Fortran code, this library supports two different
memory layouts for big arrays, one compatible with the C conventions, the other compatible with the
Fortran conventions.
In the C-style layout, array indices start at 0, and multi-dimensional arrays are laid out in row-major
format. That is, for a two-dimensional array, all elements of row 0 are contiguous in memory, followed
by all elements of row 1, etc. In other terms, the array elements at (x,y) and (x, y+1) are adjacent in
memory.
In the Fortran-style layout, array indices start at 1, and multi-dimensional arrays are laid out in
column-major format. That is, for a two-dimensional array, all elements of column 0 are contiguous in
memory, followed by all elements of column 1, etc. In other terms, the array elements at (x,y) and (x+1,
y) are adjacent in memory.
Each layout style is identified at the type level by the abstract types Bigarray.c_layout and
fortran_layout respectively.
type 'a layout
The type 'a layout represents one of the two supported memory layouts: C-style if 'a is Bigarray.c_layout
, Fortran-style if 'a is Bigarray.fortran_layout .
=== Supported layouts The abstract values c_layout and fortran_layout represent the two supported layouts
at the level of values. ===
val c_layout : c_layout layout
val fortran_layout : fortran_layout layout
=== Generic arrays (of arbitrarily many dimensions) ===
module Genarray : sig end
=== One-dimensional arrays ===
module Array1 : sig end
One-dimensional arrays. The Array1 structure provides operations similar to those of Bigarray.Genarray ,
but specialized to the case of one-dimensional arrays. (The Array2 and Array3 structures below provide
operations specialized for two- and three-dimensional arrays.) Statically knowing the number of
dimensions of the array allows faster operations, and more precise static type-checking.
=== Two-dimensional arrays ===
module Array2 : sig end
Two-dimensional arrays. The Array2 structure provides operations similar to those of Bigarray.Genarray ,
but specialized to the case of two-dimensional arrays.
=== Three-dimensional arrays ===
module Array3 : sig end
Three-dimensional arrays. The Array3 structure provides operations similar to those of Bigarray.Genarray
, but specialized to the case of three-dimensional arrays.
=== Coercions between generic big arrays and fixed-dimension big arrays ===
val genarray_of_array1 : ('a, 'b, 'c) Array1.t -> ('a, 'b, 'c) Genarray.t
Return the generic big array corresponding to the given one-dimensional big array.
val genarray_of_array2 : ('a, 'b, 'c) Array2.t -> ('a, 'b, 'c) Genarray.t
Return the generic big array corresponding to the given two-dimensional big array.
val genarray_of_array3 : ('a, 'b, 'c) Array3.t -> ('a, 'b, 'c) Genarray.t
Return the generic big array corresponding to the given three-dimensional big array.
val array1_of_genarray : ('a, 'b, 'c) Genarray.t -> ('a, 'b, 'c) Array1.t
Return the one-dimensional big array corresponding to the given generic big array. Raise
Invalid_argument if the generic big array does not have exactly one dimension.
val array2_of_genarray : ('a, 'b, 'c) Genarray.t -> ('a, 'b, 'c) Array2.t
Return the two-dimensional big array corresponding to the given generic big array. Raise
Invalid_argument if the generic big array does not have exactly two dimensions.
val array3_of_genarray : ('a, 'b, 'c) Genarray.t -> ('a, 'b, 'c) Array3.t
Return the three-dimensional big array corresponding to the given generic big array. Raise
Invalid_argument if the generic big array does not have exactly three dimensions.
=== Re-shaping big arrays ===
val reshape : ('a, 'b, 'c) Genarray.t -> int array -> ('a, 'b, 'c) Genarray.t
reshape b [|d1;...;dN|] converts the big array b to a N -dimensional array of dimensions d1 ... dN .
The returned array and the original array b share their data and have the same layout. For instance,
assuming that b is a one-dimensional array of dimension 12, reshape b [|3;4|] returns a two-dimensional
array b' of dimensions 3 and 4. If b has C layout, the element (x,y) of b' corresponds to the element x
* 3 + y of b . If b has Fortran layout, the element (x,y) of b' corresponds to the element x + (y - 1) *
4 of b . The returned big array must have exactly the same number of elements as the original big array
b . That is, the product of the dimensions of b must be equal to i1 * ... * iN . Otherwise,
Invalid_argument is raised.
val reshape_1 : ('a, 'b, 'c) Genarray.t -> int -> ('a, 'b, 'c) Array1.t
Specialized version of Bigarray.reshape for reshaping to one-dimensional arrays.
val reshape_2 : ('a, 'b, 'c) Genarray.t -> int -> int -> ('a, 'b, 'c) Array2.t
Specialized version of Bigarray.reshape for reshaping to two-dimensional arrays.
val reshape_3 : ('a, 'b, 'c) Genarray.t -> int -> int -> int -> ('a, 'b, 'c) Array3.t
Specialized version of Bigarray.reshape for reshaping to three-dimensional arrays.
OCamldoc 2016-05-05 Bigarray(3o)