Module Bigarray_ext.GenarraySource

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.

Return the number of dimensions of the given Bigarray.

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

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.

Return the layout of the given Bigarray.

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

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.

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).

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.

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.