1 use crate::stats::bivariate::Data;
2 use crate::stats::float::Float;
3 use crate::stats::rand_util::{new_rng, Rng};
4 
5 pub struct Resamples<'a, X, Y>
6 where
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))]
16 impl<'a, X, Y> Resamples<'a, X, Y>
17 where
18     X: 'a + Float,
19     Y: 'a + Float,
20 {
new(data: Data<'a, X, Y>) -> Resamples<'a, X, Y>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 
next(&mut self) -> Data<'_, X, Y>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