rust-average/tests/streaming_stats.rs
2017-05-28 21:13:47 +02:00

36 lines
1.2 KiB
Rust

#[macro_use] extern crate average;
extern crate rand;
extern crate stats;
/// Create a random vector by sampling from a normal distribution.
fn initialize_vec(size: usize) -> Vec<f64> {
use rand::distributions::{Normal, IndependentSample};
use rand::{XorShiftRng, SeedableRng};
let normal = Normal::new(2.0, 3.0);
let mut values = Vec::with_capacity(size);
let mut rng = XorShiftRng::from_seed([1, 2, 3, 4]);
for _ in 0..size {
values.push(normal.ind_sample(&mut rng));
}
values
}
#[test]
fn average_vs_streaming_stats_small() {
let values = initialize_vec(100);
let a: average::MeanWithError = values.iter().map(|x| *x).collect();
let b: stats::OnlineStats = values.iter().map(|x| *x).collect();
assert_almost_eq!(a.mean(), b.mean(), 1e-16);
assert_almost_eq!(a.population_variance(), b.variance(), 1e-14);
}
#[test]
fn average_vs_streaming_stats_large() {
let values = initialize_vec(1_000_000);
let a: average::MeanWithError = values.iter().map(|x| *x).collect();
let b: stats::OnlineStats = values.iter().map(|x| *x).collect();
assert_almost_eq!(a.mean(), b.mean(), 1e-16);
assert_almost_eq!(a.population_variance(), b.variance(), 1e-13);
}