ocaml/otherlibs/bigarray/bigarray.mli

(***********************************************************************)
(*                                                                     *)
(*                           Objective Caml                            *)
(*                                                                     *)
(*          Manuel Serrano et Xavier Leroy, INRIA Rocquencourt         *)
(*                                                                     *)
(*  Copyright 2000 Institut National de Recherche en Informatique et   *)
(*  en Automatique.  All rights reserved.  This file is distributed    *)
(*  under the terms of the GNU Library General Public License.         *)
(*                                                                     *)
(***********************************************************************)

(* $Id$ *)

(* Module [Bigarray]: 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 Caml 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 Caml ad-hoc polymorphic operations:
   comparisons ([=], [<>], [<=], etc, as well as [compare]);
   hashing (module [Hash]);
   and structured input-output ([output_value] and [input_value],
   as well as the functions from the [Marshal] module). *)

(*** Element kinds *)

type float32_elt
type float64_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
      (* Big arrays can contain elements of the following kinds:
-        IEEE single precision (32 bits) floating-point numbers;
-        IEEE double precision (64 bits) floating-point numbers;
-        8-bit integers (signed or unsigned);
-        16-bit integers (signed or unsigned);
-        Caml integers (signed, 31 bits on 32-bit architectures,
                                63 bits on 64-bit architectures);
-        32-bit signed integers;
-        64-bit signed integers;
-        platform-native signed integers (32 bits on 32-bit architectures,
                                          64 bits on 64-bit architectures).

         Each element kind is represented at the type level by one
         of the abstract types defined above. *)

type ('a, 'b) kind
      (* To each element kind is associated a Caml type, which is
         the type of Caml 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 Caml uses the Caml type [float], which is
         64-bit double precision floats.

         The abstract type [('a, 'b) kind] captures this association
         of a Caml 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 Caml types with
         element kinds: *)

val float32: (float, float32_elt) kind
val float64: (float, float64_elt) kind
val int8_signed: (int, int8_signed_elt) kind
val int8_unsigned: (int, int8_unsigned_elt) kind
val int16_signed: (int, int16_signed_elt) kind
val int16_unsigned: (int, int16_unsigned_elt) kind
val int: (int, int_elt) kind
val int32: (int32, int32_elt) kind
val int64: (int64, int64_elt) kind
val nativeint: (nativeint, nativeint_elt) kind
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 Caml type [float].  Big arrays of
         integer kinds are accessed using the smallest Caml integer
         type large enough to represent the array elements:
         [int] for 8- and 16-bit integer bigarrays, as well as Caml-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
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 [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 [c_layout], Fortran-style
         if ['a] is [fortran_layout]. *)

val c_layout: c_layout layout
val fortran_layout: fortran_layout layout
      (* The abstract values [c_layout] and [fortran_layout] represent
         the two supported layouts at the level of values.  *)

(*** Generic arrays (of arbitrarily many dimensions) *)

module Genarray: sig
  type ('a, 'b, 'c) t
      (* The type [Genarray.t] is the type of big arrays with variable
         numbers of dimensions.  Any number of dimensions between 1 and 16
         is supported.

         The three type parameters to [Genarray.t] identify the array element
         kind and layout, as follows:
-        the first parameter, ['a], is the Caml type for accessing array
         elements ([float], [int], [int32], [int64], [nativeint]);
-        the second parameter, ['b], is the actual kind of array elements
         ([float32_elt], [float64_elt], [int8_signed_elt], [int8_unsigned_elt],
          etc);
-        the third parameter, ['c], identifies the array layout
         ([c_layout] or [fortran_layout]).

         For instance, [(float, float32_elt, fortran_layout) Genarray.t]
         is the type of generic big arrays containing 32-bit floats
         in Fortran layout; reads and writes in this array use the
         Caml type [float]. *)

  external create:
    kind:('a, 'b) kind -> layout:'c layout -> dims:int array -> ('a, 'b, 'c) t
    = "bigarray_create"
      (* [Genarray.create kind layout dimensions] returns a new big array
         whose element kind is determined by the parameter [kind] (one of
         [float32], [float64], [int8_signed], etc) and whose layout is
         determined by the parameter [layout] (one of [c_layout] or
         [fortran_layout]).  The [dimensions] parameter is an array of
         integers that indicate the size of the big array in each dimension.
         The length of [dimensions] determines the number of dimensions
         of the bigarray.

         For instance, [Genarray.create int32 c_layout [|4;6;8|]]
         returns a fresh big array of 32-bit integers, in C layout,
         having three dimensions, the three dimensions being 4, 6 and 8
         respectively.

         Big arrays returned by [Genarray.create] are not initialized:
         the initial values of array elements is unspecified.

         [Genarray.create] raises [Invalid_arg] if the number of dimensions
         is not in the range 1 to 16 inclusive, or if one of the dimensions
         is negative. *)
  external num_dims: ('a, 'b, 'c) t -> int = "bigarray_num_dims"
      (* Return the number of dimensions of the given big array. *)
  external nth_dim: ('a, 'b, 'c) t -> int -> int = "bigarray_dim"
      (* [Genarray.nth_dim a n] returns the [n]-th dimension of the
         big array [a].  The first dimension corresponds to [n = 0];
         the second dimension corresponds to [n = 1]; the last dimension,
         to [n = Genarray.num_dims a - 1].
         Raise [Invalid_arg] if [n] is less than 0 or greater or equal than
         [Genarray.num_dims a]. *)
  external get: ('a, 'b, 'c) t -> int array -> 'a = "bigarray_get_generic"
      (* Read an element of a generic big array.
         [Genarray.get a [|i1; ...; iN|]] returns the element of [a]
         whose coordinates are [i1] in the first dimension, [i2] in
         the second dimension, \ldots, [iN] in the [N]-th dimension.

         If [a] has C layout, the coordinates must be greater or equal than 0
         and strictly less than the corresponding dimensions of [a].
         If [a] has Fortran layout, the coordinates must be greater or equal
         than 1 and less or equal than the corresponding dimensions of [a].
         Raise [Invalid_arg] if the array [a] does not have exactly [N]
         dimensions, or if the coordinates are outside the array bounds.

         If [N > 3], alternate syntax is provided: you can write
         [a.{i1, i2, ..., iN}] instead of [Genarray.get a [|i1; ...; iN|]].
         (The syntax [a.{...}] with one, two or three coordinates is
         reserved for accessing one-, two- and three-dimensional arrays
         as described below.) *)
  external set: ('a, 'b, 'c) t -> int array -> 'a -> unit
    = "bigarray_set_generic"
      (* Assign an element of a generic big array.
         [Genarray.set a [|i1; ...; iN|] v] stores the value [v] in the
         element of [a] whose coordinates are [i1] in the first dimension,
         [i2] in the second dimension, \ldots, [iN] in the [N]-th dimension.

         The array [a] must have exactly [N] dimensions, and all coordinates
         must lie inside the array bounds, as described for [Genarray.get];
         otherwise, [Invalid_arg] is raised.

         If [N > 3], alternate syntax is provided: you can write
         [a.{i1, i2, ..., iN} <- v] instead of
         [Genarray.set a [|i1; ...; iN|] v].
         (The syntax [a.{...} <- v] with one, two or three coordinates is
         reserved for updating one-, two- and three-dimensional arrays
         as described below.) *)
  external sub_left:
    ('a, 'b, c_layout) t -> pos:int -> len:int -> ('a, 'b, c_layout) t
    = "bigarray_sub"
      (* Extract a sub-array of the given big array by restricting the
         first (left-most) dimension.  [Genarray.sub_left a ofs len]
         returns a big array with the same number of dimensions as [a],
         and the same dimensions as [a], except the first dimension,
         which corresponds to the interval [[ofs ... ofs + len - 1]]
         of the first dimension of [a].  No copying of elements is
         involved: the sub-array and the original array share the same
         storage space.  In other terms, the element at coordinates
         [[|i1; ...; iN|]] of the sub-array is identical to the
         element at coordinates [[|i1+ofs; ...; iN|]] of the original
         array [a].

         [Genarray.sub_left] applies only to big arrays in C layout.
         Raise [Invalid_arg] if [ofs] and [len] do not designate
         a valid sub-array of [a], that is, if [ofs < 0], or [len < 0],
         or [ofs + len > Genarray.nth_dim a 0]. *)
  external sub_right:
    ('a, 'b, fortran_layout) t ->
    pos:int -> len:int -> ('a, 'b, fortran_layout) t
    = "bigarray_sub"
      (* Extract a sub-array of the given big array by restricting the
         last (right-most) dimension.  [Genarray.sub_right a ofs len]
         returns a big array with the same number of dimensions as [a],
         and the same dimensions as [a], except the last dimension,
         which corresponds to the interval [[ofs ... ofs + len - 1]]
         of the last dimension of [a].  No copying of elements is
         involved: the sub-array and the original array share the same
         storage space.  In other terms, the element at coordinates
         [[|i1; ...; iN|]] of the sub-array is identical to the
         element at coordinates [[|i1; ...; iN+ofs|]] of the original
         array [a].

         [Genarray.sub_right] applies only to big arrays in Fortran layout.
         Raise [Invalid_arg] if [ofs] and [len] do not designate
         a valid sub-array of [a], that is, if [ofs < 1], or [len < 0],
         or [ofs + len > Genarray.nth_dim a (Genarray.num_dims a - 1)]. *)
  external slice_left:
    ('a, 'b, c_layout) t -> int array -> ('a, 'b, c_layout) t
    = "bigarray_slice"
      (* Extract a sub-array of lower dimension from the given big array
         by fixing one or several of the first (left-most) coordinates.
         [Genarray.slice_left a [|i1; ... ; iM|]] returns the ``slice''
         of [a] obtained by setting the first [M] coordinates to
         [i1], \ldots, [iM].  If [a] has [N] dimensions, the slice has
         dimension [N - M], and the element at coordinates
         [[|j1; ...; j(N-M)|]] in the slice is identical to the element
         at coordinates [[|i1; ...; iM; j1; ...; j(N-M)|]] in the original
         array [a].  No copying of elements is involved: the slice and
         the original array share the same storage space.

         [Genarray.slice_left] applies only to big arrays in C layout.
         Raise [Invalid_arg] if [M >= N], or if [[|i1; ... ; iM|]]
         is outside the bounds of [a]. *)
  external slice_right:
    ('a, 'b, fortran_layout) t -> int array -> ('a, 'b, fortran_layout) t
    = "bigarray_slice"
      (* Extract a sub-array of lower dimension from the given big array
         by fixing one or several of the last (right-most) coordinates.
         [Genarray.slice_right a [|i1; ... ; iM|]] returns the ``slice''
         of [a] obtained by setting the last [M] coordinates to
         [i1], \ldots, [iM].  If [a] has [N] dimensions, the slice has
         dimension [N - M], and the element at coordinates
         [[|j1; ...; j(N-M)|]] in the slice is identical to the element
         at coordinates [[|j1; ...; j(N-M); i1; ...; iM|]] in the original
         array [a].  No copying of elements is involved: the slice and
         the original array share the same storage space.

         [Genarray.slice_right] applies only to big arrays in Fortran layout.
         Raise [Invalid_arg] if [M >= N], or if [[|i1; ... ; iM|]]
         is outside the bounds of [a]. *)
  external blit: src:('a, 'b, 'c) t -> dst:('a, 'b, 'c) t -> unit
      = "bigarray_blit"
      (* Copy all elements of a big array in another big array.
         [Genarray.blit src dst] copies all elements of [src] into
         [dst].  Both arrays [src] and [dst] must have the same number of
         dimensions and equal dimensions.  Copying a sub-array of [src]
         to a sub-array of [dst] can be achieved by applying [Genarray.blit]
         to sub-array or slices of [src] and [dst]. *)
  external fill: ('a, 'b, 'c) t -> 'a -> unit = "bigarray_fill"
      (* Set all elements of a big array to a given value.
         [Genarray.fill a v] stores the value [v] in all elements of
         the big array [a].  Setting only some elements of [a] to [v]
         can be achieved by applying [Genarray.fill] to a sub-array
         or a slice of [a]. *)
  external map_file:
    Unix.file_descr -> kind:('a, 'b) kind -> layout:'c layout ->
    shared:bool -> dims:int array -> ('a, 'b, 'c) t = "bigarray_map_file"
      (* Memory mapping of a file as a big array.
         [Genarray.map_file fd kind layout shared dims]
         returns a big array of kind [kind], layout [layout],
         and dimensions as specified in [dims].  The data contained in
         this big array are the contents of the file referred to by
         the file descriptor [fd] (as opened previously with
         [Unix.openfile], for example).  If [shared] is [true],
         all modifications performed on the array are reflected in
         the file.  This requires that [fd] be opened with write permissions.
         If [shared] is [false], modifications performed on the array
         are done in memory only, using copy-on-write of the modified
         pages; the underlying file is not affected.

         [Genarray.map_file] is much more efficient than reading
         the whole file in a big array, modifying that big array,
         and writing it afterwards.

         To adjust automatically the dimensions of the big array to
         the actual size of the file, the major dimension (that is,
         the first dimension for an array with C layout, and the last
         dimension for an array with Fortran layout) can be given as
         [-1].  [Genarray.map_file] then determines the major dimension
         from the size of the file.  The file must contain an integral
         number of sub-arrays as determined by the non-major dimensions,
         otherwise [Failure] is raised.

         If all dimensions of the big array are given, the file size is
         matched against the size of the big array.  If the file is larger
         than the big array, only the initial portion of the file is
         mapped to the big array.  If the file is smaller than the big
         array, the file is automatically grown to the size of the big array.
         This requires write permissions on [fd]. *)
end

(*** One-dimensional arrays *)

(* The [Array1] structure provides operations similar to those of
   [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. *)

module Array1: sig
  type ('a, 'b, 'c) t
        (* The type of one-dimensional big arrays whose elements have
           Caml type ['a], representation kind ['b], and memory layout ['c]. *)
  val create:
    kind:('a, 'b) kind -> layout:'c layout -> dim:int -> ('a, 'b, 'c) t
        (* [Array1.create kind layout dim] returns a new bigarray of
           one dimension, whose size is [dim].  [kind] and [layout]
           determine the array element kind and the array layout
           as described for [Genarray.create]. *)
  val dim: ('a, 'b, 'c) t -> int
        (* Return the size (dimension) of the given one-dimensional 
           big array. *)
  external get: ('a, 'b, 'c) t -> int -> 'a = "%bigarray_ref_1"
        (* [Array1.get a x], or alternatively [a.{x}], 
           returns the element of [a] at index [x].
           [x] must be greater or equal than [0] and strictly less than
           [Array1.dim a] if [a] has C layout.  If [a] has Fortran layout,
           [x] must be greater or equal than [1] and less or equal than
           [Array1.dim a].  Otherwise, [Invalid_arg] is raised. *)
  external set: ('a, 'b, 'c) t -> int -> 'a -> unit = "%bigarray_set_1"
        (* [Array1.set a x v], also written [a.{x} <- v],
           stores the value [v] at index [x] in [a].
           [x] must be inside the bounds of [a] as described in [Array1.get];
           otherwise, [Invalid_arg] is raised. *)
  external sub: ('a, 'b, 'c) t -> pos:int -> len:int -> ('a, 'b, 'c) t
    = "bigarray_sub"
        (* Extract a sub-array of the given one-dimensional big array.
           See [Genarray.sub_left] for more details. *)
  external blit: src:('a, 'b, 'c) t -> dst:('a, 'b, 'c) t -> unit
    = "bigarray_blit"
        (* Copy the first big array to the second big array.
           See [Genarray.blit] for more details. *)
  external fill: ('a, 'b, 'c) t -> 'a -> unit = "bigarray_fill"
        (* Fill the given big array with the given value.
           See [Genarray.fill] for more details. *)
  val of_array:
    kind:('a, 'b) kind -> layout:'c layout -> 'a array -> ('a, 'b, 'c) t
        (* Build a one-dimensional big array initialized from the
           given array.  *)
  val map_file: Unix.file_descr -> kind:('a, 'b) kind -> layout:'c layout ->
                shared:bool -> dim:int -> ('a, 'b, 'c) t
        (* Memory mapping of a file as a one-dimensional big array.
           See [Genarray.map_file] for more details. *)
end

(*** Two-dimensional arrays *)

(* The [Array2] structure provides operations similar to those of
   [Genarray], but specialized to the case of two-dimensional arrays. *)

module Array2: sig
  type ('a, 'b, 'c) t
        (* The type of two-dimensional big arrays whose elements have
           Caml type ['a], representation kind ['b], and memory layout ['c]. *)
  val create:
    kind:('a, 'b) kind ->
    layout:'c layout -> dim1:int -> dim2:int -> ('a, 'b, 'c) t
        (* [Array2.create kind layout dim1 dim2] returns a new bigarray of
           two dimension, whose size is [dim1] in the first dimension
           and [dim2] in the second dimension.  [kind] and [layout]
           determine the array element kind and the array layout
           as described for [Genarray.create]. *)
  val dim1: ('a, 'b, 'c) t -> int
        (* Return the first dimension of the given two-dimensional 
           big array. *)
  val dim2: ('a, 'b, 'c) t -> int
        (* Return the second dimension of the given two-dimensional 
           big array. *)
  external get: ('a, 'b, 'c) t -> int -> int -> 'a = "%bigarray_ref_2"
        (* [Array2.get a x y], also written [a.{x,y}],
           returns the element of [a] at coordinates ([x], [y]).
           [x] and [y] must be within the bounds
           of [a], as described for [Genarray.get]; otherwise, [Invalid_arg]
           is raised. *)
  external set: ('a, 'b, 'c) t -> int -> int -> 'a -> unit = "%bigarray_set_2"
        (* [Array2.set a x y v], or alternatively [a.{x,y} <- v],
           stores the value [v] at coordinates ([x], [y]) in [a].
           [x] and [y] must be within the bounds of [a],
           as described for [Genarray.set];
           otherwise, [Invalid_arg] is raised. *)
  external sub_left:
    ('a, 'b, c_layout) t -> pos:int -> len:int -> ('a, 'b, c_layout) t
    = "bigarray_sub"
        (* Extract a two-dimensional sub-array of the given two-dimensional 
           big array by restricting the first dimension.
           See [Genarray.sub_left] for more details.  [Array2.sub_left]
           applies only to arrays with C layout. *)
  external sub_right:
    ('a, 'b, fortran_layout) t ->
    pos:int -> len:int -> ('a, 'b, fortran_layout) t = "bigarray_sub"
        (* Extract a two-dimensional sub-array of the given two-dimensional 
           big array by restricting the second dimension.
           See [Genarray.sub_right] for more details.  [Array2.sub_right]
           applies only to arrays with Fortran layout. *)
  val slice_left:
    ('a, 'b, c_layout) t -> x:int -> ('a, 'b, c_layout) Array1.t
        (* Extract a row (one-dimensional slice) of the given two-dimensional
           big array.  The integer parameter is the index of the row to
           extract.  See [Genarray.slice_left] for more details.
           [Array2.slice_left] applies only to arrays with C layout. *)
  val slice_right:
    ('a, 'b, fortran_layout) t -> y:int -> ('a, 'b, fortran_layout) Array1.t
        (* Extract a column (one-dimensional slice) of the given
           two-dimensional big array.  The integer parameter is the
           index of the column to extract.  See [Genarray.slice_right] for
           more details.  [Array2.slice_right] applies only to arrays
           with Fortran layout. *)
  external blit: src:('a, 'b, 'c) t -> dst:('a, 'b, 'c) t -> unit
    = "bigarray_blit"
        (* Copy the first big array to the second big array.
           See [Genarray.blit] for more details. *)
  external fill: ('a, 'b, 'c) t -> 'a -> unit = "bigarray_fill"
        (* Fill the given big array with the given value.
           See [Genarray.fill] for more details. *)
  val of_array:
    kind:('a, 'b) kind -> layout:'c layout -> 'a array array -> ('a, 'b, 'c) t
        (* Build a two-dimensional big array initialized from the
           given array of arrays.  *)
  val map_file: Unix.file_descr -> kind:('a, 'b) kind -> layout:'c layout ->
                shared:bool -> dim1:int -> dim2:int -> ('a, 'b, 'c) t
        (* Memory mapping of a file as a two-dimensional big array.
           See [Genarray.map_file] for more details. *)
end

(*** Three-dimensional arrays *)

(* The [Array3] structure provides operations similar to those of
   [Genarray], but specialized to the case of three-dimensional arrays. *)

module Array3: sig
  type ('a, 'b, 'c) t
        (* The type of three-dimensional big arrays whose elements have
           Caml type ['a], representation kind ['b], and memory layout ['c]. *)
  val create:
    kind:('a, 'b) kind -> layout:'c layout ->
    dim1:int -> dim2:int -> dim3:int -> ('a, 'b, 'c) t
        (* [Array3.create kind layout dim1 dim2 dim3] returns a new bigarray of
           three dimension, whose size is [dim1] in the first dimension,
           [dim2] in the second dimension, and [dim3] in the third.
           [kind] and [layout] determine the array element kind and
           the array layout as described for [Genarray.create]. *)
  val dim1: ('a, 'b, 'c) t -> int
        (* Return the first dimension of the given three-dimensional 
           big array. *)
  val dim2: ('a, 'b, 'c) t -> int
        (* Return the second dimension of the given three-dimensional 
           big array. *)
  val dim3: ('a, 'b, 'c) t -> int
        (* Return the third dimension of the given three-dimensional 
           big array. *)
  external get: ('a, 'b, 'c) t -> int -> int -> int -> 'a = "%bigarray_ref_3"
        (* [Array3.get a x y z], also written [a.{x,y,z}],
           returns the element of [a] at coordinates ([x], [y], [z]).
           [x], [y] and [z] must be within the bounds of [a],
           as described for [Genarray.get]; otherwise, [Invalid_arg]
           is raised. *)
  external set: ('a, 'b, 'c) t -> int -> int -> int -> 'a -> unit = "%bigarray_set_3"
        (* [Array3.set a x y v], or alternatively [a.{x,y,z} <- v],
           stores the value [v] at coordinates ([x], [y], [z]) in [a].
           [x], [y] and [z] must be within the bounds of [a],
           as described for [Genarray.set];
           otherwise, [Invalid_arg] is raised. *)
  external sub_left:
    ('a, 'b, c_layout) t -> pos:int -> len:int -> ('a, 'b, c_layout) t
    = "bigarray_sub"
        (* Extract a three-dimensional sub-array of the given
           three-dimensional big array by restricting the first dimension.
           See [Genarray.sub_left] for more details.  [Array3.sub_left]
           applies only to arrays with C layout. *)
  external sub_right:
    ('a, 'b, fortran_layout) t ->
    pos:int -> len:int -> ('a, 'b, fortran_layout) t
    = "bigarray_sub"
        (* Extract a three-dimensional sub-array of the given
           three-dimensional big array by restricting the second dimension.
           See [Genarray.sub_right] for more details.  [Array3.sub_right]
           applies only to arrays with Fortran layout. *)
  val slice_left_1:
    ('a, 'b, c_layout) t -> x:int -> y:int -> ('a, 'b, c_layout) Array1.t
        (* Extract a one-dimensional slice of the given three-dimensional
           big array by fixing the first two coordinates.
           The integer parameters are the coordinates of the slice to
           extract.  See [Genarray.slice_left] for more details.
           [Array3.slice_left_1] applies only to arrays with C layout. *)
  val slice_right_1:
    ('a, 'b, fortran_layout) t -> y:int -> z:int -> 
        ('a, 'b, fortran_layout) Array1.t
        (* Extract a one-dimensional slice of the given three-dimensional
           big array by fixing the last two coordinates.
           The integer parameters are the coordinates of the slice to
           extract.  See [Genarray.slice_right] for more details.
           [Array3.slice_right_1] applies only to arrays with Fortran
           layout. *)
  val slice_left_2:
    ('a, 'b, c_layout) t -> x:int -> ('a, 'b, c_layout) Array2.t
        (* Extract a  two-dimensional slice of the given three-dimensional
           big array by fixing the first coordinate.
           The integer parameter is the first coordinate of the slice to
           extract.  See [Genarray.slice_left] for more details.
           [Array3.slice_left_2] applies only to arrays with C layout. *)
  val slice_right_2:
    ('a, 'b, fortran_layout) t -> z:int -> ('a, 'b, fortran_layout) Array2.t
        (* Extract a two-dimensional slice of the given
           three-dimensional big array by fixing the last coordinate.
           The integer parameter is the coordinate of the slice
           to extract.  See [Genarray.slice_right] for more details.
           [Array3.slice_right_2] applies only to arrays with Fortran
           layout. *)
  external blit: src:('a, 'b, 'c) t -> dst:('a, 'b, 'c) t -> unit
    = "bigarray_blit"
        (* Copy the first big array to the second big array.
           See [Genarray.blit] for more details. *)
  external fill: ('a, 'b, 'c) t -> 'a -> unit = "bigarray_fill"
        (* Fill the given big array with the given value.
           See [Genarray.fill] for more details. *)
  val of_array:
        kind:('a, 'b) kind -> layout:'c layout ->
        'a array array array -> ('a, 'b, 'c) t
        (* Build a three-dimensional big array initialized from the
           given array of arrays of arrays.  *)
  val map_file: Unix.file_descr -> kind:('a, 'b) kind -> layout:'c layout ->
             shared:bool -> dim1:int -> dim2:int -> dim3:int -> ('a, 'b, 'c) t
        (* Memory mapping of a file as a three-dimensional big array.
           See [Genarray.map_file] for more details. *)
end

(*** Coercions between generic big arrays and fixed-dimension big arrays *)

external genarray_of_array1: ('a, 'b, 'c) Array1.t -> ('a, 'b, 'c) Genarray.t = "%identity"
external genarray_of_array2: ('a, 'b, 'c) Array2.t -> ('a, 'b, 'c) Genarray.t = "%identity"
external genarray_of_array3: ('a, 'b, 'c) Array3.t -> ('a, 'b, 'c) Genarray.t = "%identity"
        (* Return the generic big array corresponding to the given
           one-dimensional, two-dimensional or 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_arg] 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_arg] 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_arg] if the generic big array
           does not have exactly three dimensions. *)

(*** Re-shaping big arrays *)

val reshape:
      ('a, 'b, 'c) Genarray.t -> dims: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_arg] is raised. *)
val reshape_1:
      ('a, 'b, 'c) Genarray.t -> dim:int -> ('a, 'b, 'c) Array1.t
        (* Specialized version of [reshape] for reshaping to one-dimensional
           arrays. *)
val reshape_2:
      ('a, 'b, 'c) Genarray.t -> dim1:int -> dim2:int -> ('a, 'b, 'c) Array2.t
        (* Specialized version of [reshape] for reshaping to two-dimensional
           arrays. *)
val reshape_3:
      ('a, 'b, 'c) Genarray.t -> dim1:int -> dim2:int -> dim3:int ->
      ('a, 'b, 'c) Array3.t
        (* Specialized version of [reshape] for reshaping to three-dimensional
           arrays. *)