Bigarray(3) OCaml library Bigarray(3)
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 float- ing-point numbers, thereafter referred to as 'big arrays'. The imple- mentation 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 sin- gle precision (32 bits) floating-point numbers (Bigarray.float32_elt), - IEEE double precision (64 bits) floating-point numbers (Bigar- ray.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 Bigar- ray.int8_unsigned_elt), - 16-bit integers (signed or unsigned) (Bigar- ray.int16_signed_elt or Bigarray.int16_unsigned_elt), - OCaml integers (signed, 31 bits on 32-bit architectures, 63 bits on 64-bit architec- tures) (Bigarray.int_elt), - 32-bit signed integer (Bigar- ray.int32_elt), - 64-bit signed integers (Bigarray.int64_elt), - plat- form-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 *_elt types defined below (defined with a single constructor instead of abstract types for technical injectivity reasons). === type float32_elt = | Float32_elt type float64_elt = | Float64_elt type int8_signed_elt = | Int8_signed_elt type int8_unsigned_elt = | Int8_unsigned_elt type int16_signed_elt = | Int16_signed_elt type int16_unsigned_elt = | Int16_unsigned_elt type int32_elt = | Int32_elt type int64_elt = | Int64_elt type int_elt = | Int_elt type nativeint_elt = | Nativeint_elt type complex32_elt = | Complex32_elt type complex64_elt = | Complex64_elt type ('a, 'b) kind = | Float32 : (float, float32_elt) kind | Float64 : (float, float64_elt) kind | Int8_signed : (int, int8_signed_elt) kind | Int8_unsigned : (int, int8_unsigned_elt) kind | Int16_signed : (int, int16_signed_elt) kind | Int16_unsigned : (int, int16_unsigned_elt) kind | Int32 : (int32, int32_elt) kind | Int64 : (int64, int64_elt) kind | Int : (int, int_elt) kind | Nativeint : (nativeint, nativeint_elt) kind | Complex32 : (Complex.t, complex32_elt) kind | Complex64 : (Complex.t, complex64_elt) kind | Char : (char, int8_unsigned_elt) 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 GADT 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. Its construc- tors list all possible associations of OCaml types with element kinds, and are re-exported below for backward-compatibility reasons. Using a generalized algebraic datatype (GADT) here allows to write well-typed polymorphic functions whose return type depend on the argu- ment type, such as: let zero : type a b. (a, b) kind -> a = function | Float32 -> 0.0 | Complex32 -> Complex.zero | Float64 -> 0.0 | Complex64 -> Complex.zero | Int8_signed -> 0 | Int8_unsigned -> 0 | Int16_signed -> 0 | Int16_unsigned -> 0 | Int32 -> 0l | Int64 -> 0L | Int -> 0 | Nativeint -> 0n | Char -> '\000' *) 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 repre- sent 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 = | C_layout_typ (* See Bigarray.fortran_layout . *) type fortran_layout = | Fortran_layout_typ (* 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 com- patible 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-dimen- sional 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-dimen- sional arrays are laid out in column-major format. That is, for a two-dimensional array, all elements of column 0 are contiguous in mem- ory, 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 phantom types Bigarray.c_layout and Bigarray.fortran_layout respectively. *) === Supported layouts The GADT type 'a layout represents one of the two supported memory layouts: C-style or Fortran-style. Its constructors are re-exported as values below for backward-compatibility reasons. === type 'a layout = | C_layout : c_layout layout | Fortran_layout : fortran_layout layout 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 simi- lar to those of Bigarray.Genarray , but specialized to the case of one-dimensional arrays. (The Array2 and Array3 structures below pro- vide 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 simi- lar 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 sim- ilar 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) Genar- ray.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) Genar- ray.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) Genar- ray.t Return the generic big array corresponding to the given three-dimen- sional 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' corre- sponds 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-dimen- sional 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-dimen- sional 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-dimen- sional arrays. OCamldoc 2014-10-18 Bigarray(3)
ocaml 4.02.1 - Generated Sun Oct 19 06:37:19 CDT 2014