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
use std::collections::VecDeque;
use crate::View;
#[derive(Clone)]
pub struct SMA<V> {
view: V,
window_len: usize,
q_vals: VecDeque<f64>,
sum: f64,
}
impl<V> std::fmt::Debug for SMA<V>
where
V: View,
{
fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
write!(
fmt,
"SMA(window_len: {}, q_vals: {:?}, sum: {})",
self.window_len, self.q_vals, self.sum
)
}
}
impl<V> SMA<V>
where
V: View,
{
#[inline]
pub fn new(view: V, window_len: usize) -> Self {
SMA {
view,
window_len,
q_vals: VecDeque::new(),
sum: 0.0,
}
}
}
impl<V> View for SMA<V>
where
V: View,
{
fn update(&mut self, val: f64) {
self.view.update(val);
let val = self.view.last();
if self.q_vals.len() > self.window_len {
let old_val = self.q_vals.pop_front().unwrap();
self.sum -= old_val;
}
self.q_vals.push_back(val);
self.sum += val;
}
#[inline(always)]
fn last(&self) -> f64 {
self.sum / self.q_vals.len() as f64
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::test_data::TEST_DATA;
use crate::{plot::plot_values, Echo};
use rand::{thread_rng, Rng};
#[test]
fn sma() {
let mut rng = thread_rng();
let mut sma = SMA::new(Echo::new(), 16);
for _ in 0..1024 {
let r = rng.gen::<f64>();
sma.update(r);
let last = sma.last();
assert!(last >= 0.0);
assert!(last <= 1.0);
}
}
#[test]
fn sma_plot() {
let mut sma = SMA::new(Echo::new(), 16);
let mut out: Vec<f64> = Vec::new();
for v in &TEST_DATA {
sma.update(*v);
out.push(sma.last());
}
let filename = "img/sma.png";
plot_values(out, filename).unwrap();
}
}