1use crate::stats::bivariate::Data;
2use crate::stats::float::Float;
3use crate::stats::rand_util::{new_rng, Rng};
4
5pub struct Resamples<'a, X, Y>
6where
7 X: 'a + Float,
8 Y: 'a + Float,
9{
10 rng: Rng,
11 data: (&'a [X], &'a [Y]),
12 stage: Option<(Vec<X>, Vec<Y>)>,
13}
14
15#[cfg_attr(feature = "cargo-clippy", allow(clippy::should_implement_trait))]
16impl<'a, X, Y> Resamples<'a, X, Y>
17where
18 X: 'a + Float,
19 Y: 'a + Float,
20{
21 pub fn new(data: Data<'a, X, Y>) -> Resamples<'a, X, Y> {
22 Resamples {
23 rng: new_rng(),
24 data: (data.x(), data.y()),
25 stage: None,
26 }
27 }
28
29 pub fn next(&mut self) -> Data<'_, X, Y> {
30 let n = self.data.0.len();
31
32 match self.stage {
33 None => {
34 let mut stage = (Vec::with_capacity(n), Vec::with_capacity(n));
35
36 for _ in 0..n {
37 let i = self.rng.rand_range(0u64..(self.data.0.len() as u64)) as usize;
38
39 stage.0.push(self.data.0[i]);
40 stage.1.push(self.data.1[i]);
41 }
42
43 self.stage = Some(stage);
44 }
45 Some(ref mut stage) => {
46 for i in 0..n {
47 let j = self.rng.rand_range(0u64..(self.data.0.len() as u64)) as usize;
48
49 stage.0[i] = self.data.0[j];
50 stage.1[i] = self.data.1[j];
51 }
52 }
53 }
54
55 if let Some((ref x, ref y)) = self.stage {
56 Data(x, y)
57 } else {
58 unreachable!();
59 }
60 }
61}
62