cheep-crator-2/vendor/ndarray/src/free_functions.rs

324 lines
10 KiB
Rust

// Copyright 2014-2016 bluss and ndarray developers.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use std::mem::{forget, size_of};
use alloc::slice;
use alloc::vec;
use alloc::vec::Vec;
use crate::imp_prelude::*;
use crate::{dimension, ArcArray1, ArcArray2};
/// Create an **[`Array`]** with one, two or
/// three dimensions.
///
/// ```
/// use ndarray::array;
/// let a1 = array![1, 2, 3, 4];
///
/// let a2 = array![[1, 2],
/// [3, 4]];
///
/// let a3 = array![[[1, 2], [3, 4]],
/// [[5, 6], [7, 8]]];
///
/// assert_eq!(a1.shape(), &[4]);
/// assert_eq!(a2.shape(), &[2, 2]);
/// assert_eq!(a3.shape(), &[2, 2, 2]);
/// ```
///
/// This macro uses `vec![]`, and has the same ownership semantics;
/// elements are moved into the resulting `Array`.
///
/// Use `array![...].into_shared()` to create an `ArcArray`.
#[macro_export]
macro_rules! array {
($([$([$($x:expr),* $(,)*]),+ $(,)*]),+ $(,)*) => {{
$crate::Array3::from(vec![$([$([$($x,)*],)*],)*])
}};
($([$($x:expr),* $(,)*]),+ $(,)*) => {{
$crate::Array2::from(vec![$([$($x,)*],)*])
}};
($($x:expr),* $(,)*) => {{
$crate::Array::from(vec![$($x,)*])
}};
}
/// Create a zero-dimensional array with the element `x`.
pub fn arr0<A>(x: A) -> Array0<A> {
unsafe { ArrayBase::from_shape_vec_unchecked((), vec![x]) }
}
/// Create a one-dimensional array with elements from `xs`.
pub fn arr1<A: Clone>(xs: &[A]) -> Array1<A> {
ArrayBase::from(xs.to_vec())
}
/// Create a one-dimensional array with elements from `xs`.
pub fn rcarr1<A: Clone>(xs: &[A]) -> ArcArray1<A> {
arr1(xs).into_shared()
}
/// Create a zero-dimensional array view borrowing `x`.
pub fn aview0<A>(x: &A) -> ArrayView0<'_, A> {
unsafe { ArrayView::from_shape_ptr(Ix0(), x) }
}
/// Create a one-dimensional array view with elements borrowing `xs`.
///
/// ```
/// use ndarray::aview1;
///
/// let data = [1.0; 1024];
///
/// // Create a 2D array view from borrowed data
/// let a2d = aview1(&data).into_shape((32, 32)).unwrap();
///
/// assert_eq!(a2d.sum(), 1024.0);
/// ```
pub fn aview1<A>(xs: &[A]) -> ArrayView1<'_, A> {
ArrayView::from(xs)
}
/// Create a two-dimensional array view with elements borrowing `xs`.
///
/// **Panics** if the product of non-zero axis lengths overflows `isize`. (This
/// can only occur when `V` is zero-sized.)
pub fn aview2<A, V: FixedInitializer<Elem = A>>(xs: &[V]) -> ArrayView2<'_, A> {
let cols = V::len();
let rows = xs.len();
let dim = Ix2(rows, cols);
if size_of::<V>() == 0 {
dimension::size_of_shape_checked(&dim)
.expect("Product of non-zero axis lengths must not overflow isize.");
}
// `rows` is guaranteed to fit in `isize` because we've checked the ZST
// case and slices never contain > `isize::MAX` bytes. `cols` is guaranteed
// to fit in `isize` because `FixedInitializer` is not implemented for any
// array lengths > `isize::MAX`. `cols * rows` is guaranteed to fit in
// `isize` because we've checked the ZST case and slices never contain >
// `isize::MAX` bytes.
unsafe {
let data = slice::from_raw_parts(xs.as_ptr() as *const A, cols * rows);
ArrayView::from_shape_ptr(dim, data.as_ptr())
}
}
/// Create a one-dimensional read-write array view with elements borrowing `xs`.
///
/// ```
/// use ndarray::{aview_mut1, s};
/// // Create an array view over some data, then slice it and modify it.
/// let mut data = [0; 1024];
/// {
/// let mut a = aview_mut1(&mut data).into_shape((32, 32)).unwrap();
/// a.slice_mut(s![.., ..;3]).fill(5);
/// }
/// assert_eq!(&data[..10], [5, 0, 0, 5, 0, 0, 5, 0, 0, 5]);
/// ```
pub fn aview_mut1<A>(xs: &mut [A]) -> ArrayViewMut1<'_, A> {
ArrayViewMut::from(xs)
}
/// Create a two-dimensional read-write array view with elements borrowing `xs`.
///
/// **Panics** if the product of non-zero axis lengths overflows `isize`. (This
/// can only occur when `V` is zero-sized.)
///
/// # Example
///
/// ```
/// use ndarray::aview_mut2;
///
/// // The inner (nested) array must be of length 1 to 16, but the outer
/// // can be of any length.
/// let mut data = [[0.; 2]; 128];
/// {
/// // Make a 128 x 2 mut array view then turn it into 2 x 128
/// let mut a = aview_mut2(&mut data).reversed_axes();
/// // Make the first row ones and second row minus ones.
/// a.row_mut(0).fill(1.);
/// a.row_mut(1).fill(-1.);
/// }
/// // look at the start of the result
/// assert_eq!(&data[..3], [[1., -1.], [1., -1.], [1., -1.]]);
/// ```
pub fn aview_mut2<A, V: FixedInitializer<Elem = A>>(xs: &mut [V]) -> ArrayViewMut2<'_, A> {
let cols = V::len();
let rows = xs.len();
let dim = Ix2(rows, cols);
if size_of::<V>() == 0 {
dimension::size_of_shape_checked(&dim)
.expect("Product of non-zero axis lengths must not overflow isize.");
}
// `rows` is guaranteed to fit in `isize` because we've checked the ZST
// case and slices never contain > `isize::MAX` bytes. `cols` is guaranteed
// to fit in `isize` because `FixedInitializer` is not implemented for any
// array lengths > `isize::MAX`. `cols * rows` is guaranteed to fit in
// `isize` because we've checked the ZST case and slices never contain >
// `isize::MAX` bytes.
unsafe {
let data = slice::from_raw_parts_mut(xs.as_mut_ptr() as *mut A, cols * rows);
ArrayViewMut::from_shape_ptr(dim, data.as_mut_ptr())
}
}
/// Fixed-size array used for array initialization
#[allow(clippy::missing_safety_doc)] // Should not be implemented downstream and to be deprecated.
pub unsafe trait FixedInitializer {
type Elem;
fn as_init_slice(&self) -> &[Self::Elem];
fn len() -> usize;
}
macro_rules! impl_arr_init {
(__impl $n: expr) => (
unsafe impl<T> FixedInitializer for [T; $n] {
type Elem = T;
fn as_init_slice(&self) -> &[T] { self }
fn len() -> usize { $n }
}
);
() => ();
($n: expr, $($m:expr,)*) => (
impl_arr_init!(__impl $n);
impl_arr_init!($($m,)*);
)
}
// For implementors: If you ever implement `FixedInitializer` for array lengths
// > `isize::MAX` (e.g. once Rust adds const generics), you must update
// `aview2` and `aview_mut2` to perform the necessary checks. In particular,
// the assumption that `cols` can never exceed `isize::MAX` would be incorrect.
// (Consider e.g. `let xs: &[[i32; ::std::usize::MAX]] = &[]`.)
impl_arr_init!(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,);
/// Create a two-dimensional array with elements from `xs`.
///
/// ```
/// use ndarray::arr2;
///
/// let a = arr2(&[[1, 2, 3],
/// [4, 5, 6]]);
/// assert!(
/// a.shape() == [2, 3]
/// );
/// ```
pub fn arr2<A: Clone, V: FixedInitializer<Elem = A>>(xs: &[V]) -> Array2<A>
where
V: Clone,
{
Array2::from(xs.to_vec())
}
impl<A, V> From<Vec<V>> for Array2<A>
where
V: FixedInitializer<Elem = A>,
{
/// Converts the `Vec` of arrays to an owned 2-D array.
///
/// **Panics** if the product of non-zero axis lengths overflows `isize`.
fn from(mut xs: Vec<V>) -> Self {
let dim = Ix2(xs.len(), V::len());
let ptr = xs.as_mut_ptr();
let cap = xs.capacity();
let expand_len = dimension::size_of_shape_checked(&dim)
.expect("Product of non-zero axis lengths must not overflow isize.");
forget(xs);
unsafe {
let v = if size_of::<A>() == 0 {
Vec::from_raw_parts(ptr as *mut A, expand_len, expand_len)
} else if V::len() == 0 {
Vec::new()
} else {
// Guaranteed not to overflow in this case since A is non-ZST
// and Vec never allocates more than isize bytes.
let expand_cap = cap * V::len();
Vec::from_raw_parts(ptr as *mut A, expand_len, expand_cap)
};
ArrayBase::from_shape_vec_unchecked(dim, v)
}
}
}
impl<A, V, U> From<Vec<V>> for Array3<A>
where
V: FixedInitializer<Elem = U>,
U: FixedInitializer<Elem = A>,
{
/// Converts the `Vec` of arrays to an owned 3-D array.
///
/// **Panics** if the product of non-zero axis lengths overflows `isize`.
fn from(mut xs: Vec<V>) -> Self {
let dim = Ix3(xs.len(), V::len(), U::len());
let ptr = xs.as_mut_ptr();
let cap = xs.capacity();
let expand_len = dimension::size_of_shape_checked(&dim)
.expect("Product of non-zero axis lengths must not overflow isize.");
forget(xs);
unsafe {
let v = if size_of::<A>() == 0 {
Vec::from_raw_parts(ptr as *mut A, expand_len, expand_len)
} else if V::len() == 0 || U::len() == 0 {
Vec::new()
} else {
// Guaranteed not to overflow in this case since A is non-ZST
// and Vec never allocates more than isize bytes.
let expand_cap = cap * V::len() * U::len();
Vec::from_raw_parts(ptr as *mut A, expand_len, expand_cap)
};
ArrayBase::from_shape_vec_unchecked(dim, v)
}
}
}
/// Create a two-dimensional array with elements from `xs`.
///
pub fn rcarr2<A: Clone, V: Clone + FixedInitializer<Elem = A>>(xs: &[V]) -> ArcArray2<A> {
arr2(xs).into_shared()
}
/// Create a three-dimensional array with elements from `xs`.
///
/// **Panics** if the slices are not all of the same length.
///
/// ```
/// use ndarray::arr3;
///
/// let a = arr3(&[[[1, 2],
/// [3, 4]],
/// [[5, 6],
/// [7, 8]],
/// [[9, 0],
/// [1, 2]]]);
/// assert!(
/// a.shape() == [3, 2, 2]
/// );
/// ```
pub fn arr3<A: Clone, V: FixedInitializer<Elem = U>, U: FixedInitializer<Elem = A>>(
xs: &[V],
) -> Array3<A>
where
V: Clone,
U: Clone,
{
Array3::from(xs.to_vec())
}
/// Create a three-dimensional array with elements from `xs`.
pub fn rcarr3<A: Clone, V: FixedInitializer<Elem = U>, U: FixedInitializer<Elem = A>>(
xs: &[V],
) -> ArcArray<A, Ix3>
where
V: Clone,
U: Clone,
{
arr3(xs).into_shared()
}