## table of contents

- bullseye 4.11.1-4
- testing 4.11.1-5
- unstable 4.11.1-5
- experimental 4.13.1-2

Bigarray.Genarray(3o) | OCaml library | Bigarray.Genarray(3o) |

# NAME¶

Bigarray.Genarray - no description

# Module¶

Module Bigarray.Genarray

# Documentation¶

Module **Genarray**

: **sig end**

*type* **('a, 'b, 'c)** *t*

The type **Genarray.t** is the type of Bigarrays with variable
numbers of dimensions. Any number of dimensions between 0 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 OCaml 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 Bigarrays containing 32-bit floats in
Fortran layout; reads and writes in this array use the OCaml type
**float** .

*val create* : **('a, 'b) Bigarray.kind ->** **'c
Bigarray.layout -> int array -> ('a, 'b, 'c) t**

**Genarray.create kind layout dimensions** returns a new
Bigarray 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 Bigarray 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 Bigarray of 32-bit integers, in C layout, having three
dimensions, the three dimensions being 4, 6 and 8 respectively.

Bigarrays returned by **Genarray.create** are not initialized:
the initial values of array elements is unspecified.

**Genarray.create** raises **Invalid_argument** if the
number of dimensions is not in the range 0 to 16 inclusive, or if one of the
dimensions is negative.

*val init* : **('a, 'b) Bigarray.kind ->** **'c
Bigarray.layout ->** **int array -> (int array -> 'a) -> ('a,
'b, 'c) t**

**Genarray.init kind layout dimensions f** returns a new
Bigarray **b** 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 Bigarray in each
dimension. The length of **dimensions** determines the number of
dimensions of the Bigarray.

Each element **Genarray.get b i** is initialized to the result
of **f i** . In other words, **Genarray.init kind layout dimensions
f** tabulates the results of **f** applied to the indices of a new
Bigarray whose layout is described by **kind** , **layout** and
**dimensions** . The index array **i** may be shared and mutated
between calls to f.

For instance, **Genarray.init int c_layout [|2; 1; 3|]**

(Array.fold_left (+) 0) returns a fresh Bigarray of integers, in C layout,
having three dimensions (2, 1, 3, respectively), with the element values 0,
1, 2, 1, 2, 3.

**Genarray.init** raises **Invalid_argument** if the number
of dimensions is not in the range 0 to 16 inclusive, or if one of the
dimensions is negative.

**Since** 4.12.0

*val num_dims* : **('a, 'b, 'c) t -> int**

Return the number of dimensions of the given Bigarray.

*val dims* : **('a, 'b, 'c) t -> int array**

**Genarray.dims a** returns all dimensions of the Bigarray
**a** , as an array of integers of length **Genarray.num_dims a**
.

*val nth_dim* : **('a, 'b, 'c) t -> int -> int**

**Genarray.nth_dim a n** returns the **n** -th dimension of
the Bigarray **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** .

**Raises Invalid_argument** if **n** is less than 0 or
greater or equal than **Genarray.num_dims a** .

*val kind* : **('a, 'b, 'c) t -> ('a, 'b)
Bigarray.kind**

Return the kind of the given Bigarray.

*val layout* : **('a, 'b, 'c) t -> 'c
Bigarray.layout**

Return the layout of the given Bigarray.

*val change_layout* : **('a, 'b, 'c) t ->** **'d
Bigarray.layout -> ('a, 'b, 'd) t**

**Genarray.change_layout a layout** returns a Bigarray with the
specified **layout** , sharing the data with **a** (and hence having
the same dimensions as **a** ). No copying of elements is involved: the
new array and the original array share the same storage space. The
dimensions are reversed, such that **get v [| a; b |]** in C layout
becomes **get v [| b+1; a+1 |]** in Fortran layout.

**Since** 4.04.0

*val size_in_bytes* : **('a, 'b, 'c) t -> int**

**size_in_bytes a** is the number of elements in **a**
multiplied by **a** 's **Bigarray.kind_size_in_bytes** .

**Since** 4.03.0

*val get* : **('a, 'b, 'c) t -> int array ->
'a**

Read an element of a generic Bigarray. **Genarray.get a [|i1;
...; iN|]** returns the element of **a** whose coordinates are
**i1** in the first dimension, **i2** in the second dimension, ...,
**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** .

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.)

**Raises Invalid_argument** if the array **a** does not have
exactly **N** dimensions, or if the coordinates are outside the array
bounds.

*val set* : **('a, 'b, 'c) t -> int array -> 'a ->
unit**

Assign an element of a generic Bigarray. **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, ..., **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_argument** 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.)

*val sub_left* : **('a, 'b, Bigarray.c_layout) t ->**
**int -> int -> ('a, 'b, Bigarray.c_layout) t**

Extract a sub-array of the given Bigarray by restricting the first
(left-most) dimension. **Genarray.sub_left a ofs len** returns a Bigarray
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 Bigarrays in C
layout.

**Raises Invalid_argument** 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** .

*val sub_right* : **('a, 'b, Bigarray.fortran_layout) t
->** **int -> int -> ('a, 'b, Bigarray.fortran_layout) t**

Extract a sub-array of the given Bigarray by restricting the last
(right-most) dimension. **Genarray.sub_right a ofs len** returns a
Bigarray 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 Bigarrays in Fortran
layout.

**Raises Invalid_argument** 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)** .

*val slice_left* : **('a, 'b, Bigarray.c_layout) t ->**
**int array -> ('a, 'b, Bigarray.c_layout) t**

Extract a sub-array of lower dimension from the given Bigarray 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** ,
..., **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 Bigarrays in C
layout.

**Raises Invalid_argument** if **M >= N** , or if
**[|i1; ... ; iM|]** is outside the bounds of **a** .

*val slice_right* : **('a, 'b, Bigarray.fortran_layout) t
->** **int array -> ('a, 'b, Bigarray.fortran_layout) t**

Extract a sub-array of lower dimension from the given Bigarray 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** ,
..., **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 Bigarrays in Fortran
layout.

**Raises Invalid_argument** if **M >= N** , or if
**[|i1; ... ; iM|]** is outside the bounds of **a** .

*val blit* : **('a, 'b, 'c) t -> ('a, 'b, 'c) t ->
unit**

Copy all elements of a Bigarray in another Bigarray.
**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** .

*val fill* : **('a, 'b, 'c) t -> 'a -> unit**

Set all elements of a Bigarray to a given value. **Genarray.fill
a v** stores the value **v** in all elements of the Bigarray **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** .

2021-12-22 | OCamldoc |