rust-average/tests/skewness.rs
2017-05-28 23:46:15 +02:00

56 lines
1.7 KiB
Rust

#[macro_use] extern crate average;
extern crate core;
use core::iter::Iterator;
use average::Skewness;
#[test]
fn trivial() {
let mut a = Skewness::new();
assert_eq!(a.len(), 0);
a.add(1.0);
assert_eq!(a.mean(), 1.0);
assert_eq!(a.len(), 1);
assert_eq!(a.sample_variance(), 0.0);
assert_eq!(a.population_variance(), 0.0);
assert_eq!(a.error_mean(), 0.0);
assert_eq!(a.skewness(), 0.0);
a.add(1.0);
assert_eq!(a.mean(), 1.0);
assert_eq!(a.len(), 2);
assert_eq!(a.sample_variance(), 0.0);
assert_eq!(a.population_variance(), 0.0);
assert_eq!(a.error_mean(), 0.0);
assert_eq!(a.skewness(), 0.0);
}
#[test]
fn simple() {
let mut a: Skewness = (1..6).map(f64::from).collect();
assert_eq!(a.mean(), 3.0);
assert_eq!(a.len(), 5);
assert_eq!(a.sample_variance(), 2.5);
assert_almost_eq!(a.error_mean(), f64::sqrt(0.5), 1e-16);
assert_eq!(a.skewness(), 0.0);
a.add(1.0);
assert_almost_eq!(a.skewness(), 0.2795084971874741, 1e-15);
}
#[test]
fn merge() {
let sequence: &[f64] = &[1., 2., 3., -4., 5., 6., 7., 8., 9., 1.];
for mid in 0..sequence.len() {
let (left, right) = sequence.split_at(mid);
let avg_total: Skewness = sequence.iter().map(|x| *x).collect();
let mut avg_left: Skewness = left.iter().map(|x| *x).collect();
let avg_right: Skewness = right.iter().map(|x| *x).collect();
avg_left.merge(&avg_right);
assert_eq!(avg_total.len(), avg_left.len());
assert_almost_eq!(avg_total.mean(), avg_left.mean(), 1e-14);
assert_almost_eq!(avg_total.sample_variance(), avg_left.sample_variance(), 1e-14);
assert_almost_eq!(avg_total.skewness(), avg_left.skewness(), 1e-14);
}
}