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

Big arrays support all the OCaml ad-hoc polymorphic operations:

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`

).

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`

).

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

The abstract type

`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:
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
See

`Bigarray.char`

.
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`

.
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

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

Each layout style is identified at the type level by the abstract types

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.
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.
Return the generic big array corresponding to the given one-dimensional
big array.

Return the generic big array corresponding to the given two-dimensional
big array.

Return the generic big array corresponding to the given three-dimensional
big array.

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.
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.
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.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.
Specialized version of

`Bigarray.reshape`

for reshaping to
one-dimensional arrays.int -> int -> ('a, 'b, 'c) Array2.t

Specialized version of

`Bigarray.reshape`

for reshaping to
two-dimensional arrays.int -> int -> int -> ('a, 'b, 'c) Array3.t

Specialized version of

`Bigarray.reshape`

for reshaping to
three-dimensional arrays.