|
1 |
| -use crate::imp_prelude::*; |
2 |
| -use num_complex::Complex; |
3 |
| -use rawpointer::PointerExt; |
4 |
| -use std::mem; |
5 |
| -use std::ptr::NonNull; |
6 |
| - |
7 | 1 | mod impl_numeric;
|
8 |
| - |
9 |
| -impl<T, S, D> ArrayBase<S, D> |
10 |
| -where |
11 |
| - S: Data<Elem = Complex<T>>, |
12 |
| - D: Dimension, |
13 |
| -{ |
14 |
| - /// Returns views of the real and imaginary components of the elements. |
15 |
| - /// |
16 |
| - /// ``` |
17 |
| - /// use ndarray::prelude::*; |
18 |
| - /// use num_complex::{Complex, Complex64}; |
19 |
| - /// |
20 |
| - /// let arr = array![ |
21 |
| - /// [Complex64::new(1., 2.), Complex64::new(3., 4.)], |
22 |
| - /// [Complex64::new(5., 6.), Complex64::new(7., 8.)], |
23 |
| - /// [Complex64::new(9., 10.), Complex64::new(11., 12.)], |
24 |
| - /// ]; |
25 |
| - /// let Complex { re, im } = arr.view_re_im(); |
26 |
| - /// assert_eq!(re, array![[1., 3.], [5., 7.], [9., 11.]]); |
27 |
| - /// assert_eq!(im, array![[2., 4.], [6., 8.], [10., 12.]]); |
28 |
| - /// ``` |
29 |
| - pub fn view_re_im(&self) -> Complex<ArrayView<'_, T, D>> { |
30 |
| - debug_assert!(self.pointer_is_inbounds()); |
31 |
| - |
32 |
| - let dim = self.dim.clone(); |
33 |
| - |
34 |
| - // Double the strides. In the zero-sized element case and for axes of |
35 |
| - // length <= 1, we leave the strides as-is to avoid possible overflow. |
36 |
| - let mut strides = self.strides.clone(); |
37 |
| - if mem::size_of::<T>() != 0 { |
38 |
| - for ax in 0..strides.ndim() { |
39 |
| - if dim[ax] > 1 { |
40 |
| - strides[ax] *= 2; |
41 |
| - } |
42 |
| - } |
43 |
| - } |
44 |
| - |
45 |
| - let ptr_re: NonNull<T> = self.ptr.cast(); |
46 |
| - let ptr_im: NonNull<T> = if self.is_empty() { |
47 |
| - // In the empty case, we can just reuse the existing pointer since |
48 |
| - // it won't be dereferenced anyway. It is not safe to offset by one |
49 |
| - // since the allocation may be empty. |
50 |
| - ptr_re |
51 |
| - } else { |
52 |
| - // In the nonempty case, we can safely offset into the first |
53 |
| - // (complex) element. |
54 |
| - unsafe { ptr_re.add(1) } |
55 |
| - }; |
56 |
| - |
57 |
| - // `Complex` is `repr(C)` with only fields `re: T` and `im: T`. So, the |
58 |
| - // real components of the elements start at the same pointer, and the |
59 |
| - // imaginary components start at the pointer offset by one, with |
60 |
| - // exactly double the strides. The new, doubled strides still meet the |
61 |
| - // overflow constraints: |
62 |
| - // |
63 |
| - // - For the zero-sized element case, the strides are unchanged in |
64 |
| - // units of bytes and in units of the element type. |
65 |
| - // |
66 |
| - // - For the nonzero-sized element case: |
67 |
| - // |
68 |
| - // - In units of bytes, the strides are unchanged. |
69 |
| - // |
70 |
| - // - Since `Complex<T>` for nonzero `T` is always at least 2 bytes, |
71 |
| - // and the original strides did not overflow in units of bytes, we |
72 |
| - // know that the new doubled strides will not overflow in units of |
73 |
| - // `T`. |
74 |
| - unsafe { |
75 |
| - Complex { |
76 |
| - re: ArrayView::new(ptr_re, dim.clone(), strides.clone()), |
77 |
| - im: ArrayView::new(ptr_im, dim, strides), |
78 |
| - } |
79 |
| - } |
80 |
| - } |
81 |
| - |
82 |
| - /// Returns mutable views of the real and imaginary components of the elements. |
83 |
| - /// |
84 |
| - /// ``` |
85 |
| - /// use ndarray::prelude::*; |
86 |
| - /// use num_complex::{Complex, Complex64}; |
87 |
| - /// |
88 |
| - /// let mut arr = array![ |
89 |
| - /// [Complex64::new(1., 2.), Complex64::new(3., 4.)], |
90 |
| - /// [Complex64::new(5., 6.), Complex64::new(7., 8.)], |
91 |
| - /// [Complex64::new(9., 10.), Complex64::new(11., 12.)], |
92 |
| - /// ]; |
93 |
| - /// |
94 |
| - /// let Complex { mut re, mut im } = arr.view_mut_re_im(); |
95 |
| - /// assert_eq!(re, array![[1., 3.], [5., 7.], [9., 11.]]); |
96 |
| - /// assert_eq!(im, array![[2., 4.], [6., 8.], [10., 12.]]); |
97 |
| - /// |
98 |
| - /// re[[0, 1]] = 13.; |
99 |
| - /// im[[2, 0]] = 14.; |
100 |
| - /// |
101 |
| - /// assert_eq!(arr[[0, 1]], Complex64::new(13., 4.)); |
102 |
| - /// assert_eq!(arr[[2, 0]], Complex64::new(9., 14.)); |
103 |
| - /// ``` |
104 |
| - pub fn view_mut_re_im(&mut self) -> Complex<ArrayViewMut<'_, T, D>> |
105 |
| - where |
106 |
| - S: DataMut, |
107 |
| - { |
108 |
| - self.ensure_unique(); |
109 |
| - |
110 |
| - let dim = self.dim.clone(); |
111 |
| - |
112 |
| - // Double the strides. In the zero-sized element case and for axes of |
113 |
| - // length <= 1, we leave the strides as-is to avoid possible overflow. |
114 |
| - let mut strides = self.strides.clone(); |
115 |
| - if mem::size_of::<T>() != 0 { |
116 |
| - for ax in 0..strides.ndim() { |
117 |
| - if dim[ax] > 1 { |
118 |
| - strides[ax] *= 2; |
119 |
| - } |
120 |
| - } |
121 |
| - } |
122 |
| - |
123 |
| - let ptr_re: NonNull<T> = self.ptr.cast(); |
124 |
| - let ptr_im: NonNull<T> = if self.is_empty() { |
125 |
| - // In the empty case, we can just reuse the existing pointer since |
126 |
| - // it won't be dereferenced anyway. It is not safe to offset by one |
127 |
| - // since the allocation may be empty. |
128 |
| - ptr_re |
129 |
| - } else { |
130 |
| - // In the nonempty case, we can safely offset into the first |
131 |
| - // (complex) element. |
132 |
| - unsafe { ptr_re.add(1) } |
133 |
| - }; |
134 |
| - |
135 |
| - // `Complex` is `repr(C)` with only fields `re: T` and `im: T`. So, the |
136 |
| - // real components of the elements start at the same pointer, and the |
137 |
| - // imaginary components start at the pointer offset by one, with |
138 |
| - // exactly double the strides. The new, doubled strides still meet the |
139 |
| - // overflow constraints: |
140 |
| - // |
141 |
| - // - For the zero-sized element case, the strides are unchanged in |
142 |
| - // units of bytes and in units of the element type. |
143 |
| - // |
144 |
| - // - For the nonzero-sized element case: |
145 |
| - // |
146 |
| - // - In units of bytes, the strides are unchanged. |
147 |
| - // |
148 |
| - // - Since `Complex<T>` for nonzero `T` is always at least 2 bytes, |
149 |
| - // and the original strides did not overflow in units of bytes, we |
150 |
| - // know that the new doubled strides will not overflow in units of |
151 |
| - // `T`. |
152 |
| - unsafe { |
153 |
| - Complex { |
154 |
| - re: ArrayViewMut::new(ptr_re, dim.clone(), strides.clone()), |
155 |
| - im: ArrayViewMut::new(ptr_im, dim, strides), |
156 |
| - } |
157 |
| - } |
158 |
| - } |
159 |
| -} |
0 commit comments