br_maths/
stats.rs

1use std::fmt::Display;
2
3/// 样本偏差值
4pub fn stdev<T: Display + std::fmt::Debug>(array: Vec<T>) -> f64 {
5    let len = array.len();
6    if len <= 1 {
7        return 0.0;
8    }
9    let mut total = 0.0;
10    let mut values = vec![];
11    for item in array {
12        let value = item.to_string().parse::<f64>().unwrap();
13        values.push(value);
14        total += value;
15    }
16    let mean = total / len.to_string().parse::<f64>().unwrap();
17    total = 0.0;
18    let _: Vec<f64> = values.iter_mut().map(|val| {
19        let t = (*val - mean).powi(2);
20        total += t;
21        t
22    }).collect();
23    (total / (len - 1) as f64).sqrt()
24}
25
26/// 样本标准差 (n)
27pub fn stdevp<T: Display + std::fmt::Debug>(array: Vec<T>) -> f64 {
28    let len = array.len();
29    if len <= 1 {
30        return 0.0;
31    }
32    let mut total = 0.0;
33    let mut values = vec![];
34    for item in array {
35        let value = item.to_string().parse::<f64>().unwrap();
36        values.push(value);
37        total += value;
38    }
39    let mean = total / len.to_string().parse::<f64>().unwrap();
40    total = 0.0;
41    let _: Vec<f64> = values.iter_mut().map(|val| {
42        let t = (*val - mean).powi(2);
43        total += t;
44        t
45    }).collect();
46    (total / (len) as f64).sqrt()
47}
48
49/// 方差 变差 (n-1)
50pub fn variance(array: Vec<f64>) -> f64 {
51    let len = array.len();
52    if len <= 1 {
53        return 0.0;
54    }
55    let mut total = 0.0;
56    for item in array.clone() {
57        total += item;
58    }
59    let mean = total / len.to_string().parse::<f64>().unwrap();
60    total = 0.0;
61    for item in array {
62        let t = (item - mean).powi(2);
63        total += t;
64    }
65    total / (len - 1) as f64
66}
67
68/// 方差 变差 (n)
69pub fn variancep(array: Vec<f64>) -> f64 {
70    let len = array.len();
71    if len <= 1 {
72        return 0.0;
73    }
74    let mut total = 0.0;
75    for item in array.clone() {
76        total += item;
77    }
78    let mean = total / len.to_string().parse::<f64>().unwrap();
79    total = 0.0;
80    for item in array {
81        let t = (item - mean).powi(2);
82        total += t;
83    }
84    total / (len) as f64
85}
br_maths/stats.rs

br_maths/
stats.rs
