ferray-ufunc 0.2.7

Universal functions and SIMD-accelerated elementwise operations for ferray
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149

// ferray-ufunc: Complex number functions
//
// real, imag, conj, conjugate, angle, abs (returns real magnitude)

use ferray_core::Array;
use ferray_core::dimension::Dimension;
use ferray_core::dtype::Element;
use ferray_core::error::FerrayResult;
use num_complex::Complex;
use num_traits::Float;

/// Extract the real part of a complex array.
///
/// Works with `Complex<f32>` and `Complex<f64>` arrays.
pub fn real<T, D>(input: &Array<Complex<T>, D>) -> FerrayResult<Array<T, D>>
where
    T: Element + Float,
    Complex<T>: Element,
    D: Dimension,
{
    let data: Vec<T> = input.iter().map(|c| c.re).collect();
    Array::from_vec(input.dim().clone(), data)
}

/// Extract the imaginary part of a complex array.
pub fn imag<T, D>(input: &Array<Complex<T>, D>) -> FerrayResult<Array<T, D>>
where
    T: Element + Float,
    Complex<T>: Element,
    D: Dimension,
{
    let data: Vec<T> = input.iter().map(|c| c.im).collect();
    Array::from_vec(input.dim().clone(), data)
}

/// Compute the complex conjugate.
pub fn conj<T, D>(input: &Array<Complex<T>, D>) -> FerrayResult<Array<Complex<T>, D>>
where
    T: Element + Float,
    Complex<T>: Element,
    D: Dimension,
{
    let data: Vec<Complex<T>> = input.iter().map(|c| c.conj()).collect();
    Array::from_vec(input.dim().clone(), data)
}

/// Alias for [`conj`].
pub fn conjugate<T, D>(input: &Array<Complex<T>, D>) -> FerrayResult<Array<Complex<T>, D>>
where
    T: Element + Float,
    Complex<T>: Element,
    D: Dimension,
{
    conj(input)
}

/// Compute the angle (argument/phase) of complex numbers.
///
/// Returns values in radians, in the range [-pi, pi].
pub fn angle<T, D>(input: &Array<Complex<T>, D>) -> FerrayResult<Array<T, D>>
where
    T: Element + Float,
    Complex<T>: Element,
    D: Dimension,
{
    let data: Vec<T> = input.iter().map(|c| c.im.atan2(c.re)).collect();
    Array::from_vec(input.dim().clone(), data)
}

/// Compute the absolute value (magnitude) of complex numbers.
///
/// Returns a real array.
pub fn abs<T, D>(input: &Array<Complex<T>, D>) -> FerrayResult<Array<T, D>>
where
    T: Element + Float,
    Complex<T>: Element,
    D: Dimension,
{
    let data: Vec<T> = input
        .iter()
        .map(|c| (c.re * c.re + c.im * c.im).sqrt())
        .collect();
    Array::from_vec(input.dim().clone(), data)
}

#[cfg(test)]
mod tests {
    use super::*;
    use ferray_core::dimension::Ix1;
    use num_complex::Complex64;

    fn arr1_c64(data: Vec<Complex64>) -> Array<Complex64, Ix1> {
        let n = data.len();
        Array::from_vec(Ix1::new([n]), data).unwrap()
    }

    #[test]
    fn test_real() {
        let a = arr1_c64(vec![Complex64::new(1.0, 2.0), Complex64::new(3.0, 4.0)]);
        let r = real(&a).unwrap();
        assert_eq!(r.as_slice().unwrap(), &[1.0, 3.0]);
    }

    #[test]
    fn test_imag() {
        let a = arr1_c64(vec![Complex64::new(1.0, 2.0), Complex64::new(3.0, 4.0)]);
        let r = imag(&a).unwrap();
        assert_eq!(r.as_slice().unwrap(), &[2.0, 4.0]);
    }

    #[test]
    fn test_conj() {
        let a = arr1_c64(vec![Complex64::new(1.0, 2.0), Complex64::new(3.0, -4.0)]);
        let r = conj(&a).unwrap();
        let s = r.as_slice().unwrap();
        assert_eq!(s[0], Complex64::new(1.0, -2.0));
        assert_eq!(s[1], Complex64::new(3.0, 4.0));
    }

    #[test]
    fn test_conjugate_alias() {
        let a = arr1_c64(vec![Complex64::new(1.0, 2.0)]);
        let r = conjugate(&a).unwrap();
        assert_eq!(r.as_slice().unwrap()[0], Complex64::new(1.0, -2.0));
    }

    #[test]
    fn test_angle() {
        let a = arr1_c64(vec![
            Complex64::new(1.0, 0.0),
            Complex64::new(0.0, 1.0),
            Complex64::new(-1.0, 0.0),
        ]);
        let r = angle(&a).unwrap();
        let s = r.as_slice().unwrap();
        assert!((s[0] - 0.0).abs() < 1e-12);
        assert!((s[1] - std::f64::consts::FRAC_PI_2).abs() < 1e-12);
        assert!((s[2] - std::f64::consts::PI).abs() < 1e-12);
    }

    #[test]
    fn test_abs() {
        let a = arr1_c64(vec![Complex64::new(3.0, 4.0), Complex64::new(0.0, 1.0)]);
        let r = abs(&a).unwrap();
        let s = r.as_slice().unwrap();
        assert!((s[0] - 5.0).abs() < 1e-12);
        assert!((s[1] - 1.0).abs() < 1e-12);
    }
}