common_function/scalars/vector/distance/
dot.rs

1// Copyright 2023 Greptime Team
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use nalgebra::DVectorView;
16
17/// Calculates the dot product between two vectors.
18///
19/// **Note:** Must ensure that the length of the two vectors are the same.
20pub fn dot(lhs: &[f32], rhs: &[f32]) -> f32 {
21    let lhs = DVectorView::from_slice(lhs, lhs.len());
22    let rhs = DVectorView::from_slice(rhs, rhs.len());
23
24    lhs.dot(&rhs)
25}
26
27#[cfg(test)]
28mod tests {
29    use approx::assert_relative_eq;
30
31    use super::*;
32
33    #[test]
34    fn test_dot_scalar() {
35        let lhs = vec![1.0, 2.0, 3.0];
36        let rhs = vec![1.0, 2.0, 3.0];
37        assert_relative_eq!(dot(&lhs, &rhs), 14.0, epsilon = 1e-2);
38
39        let lhs = vec![1.0, 2.0, 3.0];
40        let rhs = vec![4.0, 5.0, 6.0];
41        assert_relative_eq!(dot(&lhs, &rhs), 32.0, epsilon = 1e-2);
42
43        let lhs = vec![1.0, 2.0, 3.0];
44        let rhs = vec![7.0, 8.0, 9.0];
45        assert_relative_eq!(dot(&lhs, &rhs), 50.0, epsilon = 1e-2);
46
47        let lhs = vec![0.0, 0.0, 0.0];
48        let rhs = vec![1.0, 2.0, 3.0];
49        assert_relative_eq!(dot(&lhs, &rhs), 0.0, epsilon = 1e-2);
50
51        let lhs = vec![0.0, 0.0, 0.0];
52        let rhs = vec![4.0, 5.0, 6.0];
53        assert_relative_eq!(dot(&lhs, &rhs), 0.0, epsilon = 1e-2);
54
55        let lhs = vec![0.0, 0.0, 0.0];
56        let rhs = vec![7.0, 8.0, 9.0];
57        assert_relative_eq!(dot(&lhs, &rhs), 0.0, epsilon = 1e-2);
58
59        let lhs = vec![7.0, 8.0, 9.0];
60        let rhs = vec![1.0, 2.0, 3.0];
61        assert_relative_eq!(dot(&lhs, &rhs), 50.0, epsilon = 1e-2);
62
63        let lhs = vec![7.0, 8.0, 9.0];
64        let rhs = vec![4.0, 5.0, 6.0];
65        assert_relative_eq!(dot(&lhs, &rhs), 122.0, epsilon = 1e-2);
66
67        let lhs = vec![7.0, 8.0, 9.0];
68        let rhs = vec![7.0, 8.0, 9.0];
69        assert_relative_eq!(dot(&lhs, &rhs), 194.0, epsilon = 1e-2);
70    }
71}
common_function/scalars/vector/distance/dot.rs

common_function/scalars/vector/distance/
dot.rs
