Struct ArrayBuilder 

pub struct ArrayBuilder<T, D>(/* private fields */);

Generic builder for N-dimensional arrays.

Where MatrixBuilder targets exactly 2D and VectorBuilder targets exactly 1D, ArrayBuilder works with any ndarray::Dimension and is useful when the shape is determined at runtime.

Examples

use scirs2_core::builders::ArrayBuilder;

let a2 = ArrayBuilder::<f64, _>::zeros(ndarray::Ix2(3, 4));
assert_eq!(a2.shape(), &[3, 4]);

let a3 = ArrayBuilder::<f64, _>::zeros(ndarray::Ix3(2, 3, 4));
assert_eq!(a3.shape(), &[2, 3, 4]);

// Dynamic dimension
let ad = ArrayBuilder::<f64, ndarray::IxDyn>::zeros_dyn(&[2, 3, 4]);
assert_eq!(ad.shape(), &[2, 3, 4]);

Implementations

impl<T, D> ArrayBuilder<T, D>

where T: Clone + Zero, D: Dimension,

pub fn zeros<Sh>(shape: Sh) -> Array<T, D>

where Sh: IntoDimension<Dim = D>,

Create a zeros array with the given shape.

use scirs2_core::builders::ArrayBuilder;

let a = ArrayBuilder::<f64, _>::zeros(ndarray::Ix2(3, 4));
assert_eq!(a.shape(), &[3, 4]);

pub fn full<Sh>(shape: Sh, value: T) -> Array<T, D>

where Sh: IntoDimension<Dim = D>,

Create an array filled with a constant value.

use scirs2_core::builders::ArrayBuilder;

let a = ArrayBuilder::<i32, _>::full(ndarray::Ix2(2, 3), 7);
assert_eq!(a[[0, 0]], 7);

pub fn from_fn<Sh, F>(shape: Sh, f: F) -> Array<T, D>

where Sh: IntoDimension<Dim = D>, F: FnMut(D::Pattern) -> T,

Create an array where each element is produced by a closure receiving the dimension pattern (e.g. (row, col) for 2D, (i, j, k) for 3D, etc.).

use scirs2_core::builders::ArrayBuilder;

// 3×3 matrix: element = row + col
let a = ArrayBuilder::<usize, ndarray::Ix2>::from_fn(
    ndarray::Ix2(3, 3),
    |(r, c)| r + c,
);
assert_eq!(a[[2, 2]], 4);

pub fn from_vec<Sh>(data: Vec<T>, shape: Sh) -> CoreResult<Array<T, D>>

where Sh: IntoDimension<Dim = D>,

Build an array from a flat Vec of elements in C-order (row-major).

Returns a CoreError if the element count does not match the given shape.

use scirs2_core::builders::ArrayBuilder;

let a = ArrayBuilder::<f64, ndarray::Ix2>::from_vec(
    vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0],
    ndarray::Ix2(2, 3),
).expect("element count matches");
assert_eq!(a[[1, 2]], 6.0);

impl<T> ArrayBuilder<T, IxDyn>

where T: Clone + Zero,

pub fn zeros_dyn(shape: &[usize]) -> ArrayD<T>

Create a dynamic-dimensional zeros array from a runtime shape slice.

use scirs2_core::builders::ArrayBuilder;

let a = ArrayBuilder::<f64, ndarray::IxDyn>::zeros_dyn(&[2, 3, 4]);
assert_eq!(a.ndim(), 3);
assert_eq!(a.shape(), &[2, 3, 4]);

pub fn full_dyn(shape: &[usize], value: T) -> ArrayD<T>

Create a dynamic-dimensional array filled with value.