use rand::{Rng, seq::*};
use average::Variance;
pub fn bootstrap<F, R, N1>(mut rng: R, samples: usize, data: &[N1], reduction: F) -> (f64, f64)
where F: Fn (&[&N1]) -> f64,
R: Rng,
{
let mut bootstrap_sample = Vec::with_capacity(data.len());
let variance: Variance =
(0..samples).map(|_|
{
bootstrap_sample.clear();
bootstrap_sample.extend(
(0..data.len())
.map(|_|
{
data.choose(&mut rng).unwrap()
}
)
);
reduction(&bootstrap_sample)
}
).collect();
let mean = variance.mean();
let variance = variance.population_variance();
(mean, variance)
}
pub fn bootstrap_copyable<F, R, N1>(mut rng: R, samples: usize, data: &[N1], reduction: F) -> (f64, f64)
where F: Fn (&mut [N1]) -> f64,
R: Rng,
N1: Copy
{
let mut bootstrap_sample = Vec::with_capacity(data.len());
let variance: Variance =
(0..samples).map(|_|
{
bootstrap_sample.clear();
bootstrap_sample.extend(
(0..data.len())
.map(|_|
{
data.choose(&mut rng).unwrap()
}
)
);
reduction(&mut bootstrap_sample)
}
).collect();
let mean = variance.mean();
let variance = variance.population_variance();
(mean, variance)
}