70 lines
2.2 KiB
Rust
70 lines
2.2 KiB
Rust
#![cfg_attr(feature = "cargo-clippy", allow(float_cmp, map_clone))]
|
|
|
|
use core::iter::Iterator;
|
|
|
|
use average::{MeanWithError, Estimate, Merge, assert_almost_eq};
|
|
|
|
#[test]
|
|
fn trivial() {
|
|
let mut a = MeanWithError::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(), 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(), 0.0);
|
|
}
|
|
|
|
#[test]
|
|
fn simple() {
|
|
let a: MeanWithError = (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(), f64::sqrt(0.5), 1e-16);
|
|
}
|
|
|
|
#[cfg(feature = "serde1")]
|
|
#[test]
|
|
fn simple_serde() {
|
|
let a: MeanWithError = (1..6).map(f64::from).collect();
|
|
let b = serde_json::to_string(&a).unwrap();
|
|
assert_eq!(&b, "{\"avg\":{\"avg\":3.0,\"n\":5},\"sum_2\":10.0}");
|
|
let c: MeanWithError = serde_json::from_str(&b).unwrap();
|
|
assert_eq!(c.mean(), 3.0);
|
|
assert_eq!(c.len(), 5);
|
|
assert_eq!(c.sample_variance(), 2.5);
|
|
assert_almost_eq!(c.error(), f64::sqrt(0.5), 1e-16);
|
|
}
|
|
|
|
#[test]
|
|
fn numerically_unstable() {
|
|
// The naive algorithm fails for this example due to cancelation.
|
|
let big = 1e9;
|
|
let sample = &[big + 4., big + 7., big + 13., big + 16.];
|
|
let a: MeanWithError = sample.iter().collect();
|
|
assert_eq!(a.sample_variance(), 30.);
|
|
}
|
|
|
|
#[test]
|
|
fn merge() {
|
|
let sequence: &[f64] = &[1., 2., 3., 4., 5., 6., 7., 8., 9.];
|
|
for mid in 0..sequence.len() {
|
|
let (left, right) = sequence.split_at(mid);
|
|
let avg_total: MeanWithError = sequence.iter().collect();
|
|
let mut avg_left: MeanWithError = left.iter().collect();
|
|
let avg_right: MeanWithError = right.iter().collect();
|
|
avg_left.merge(&avg_right);
|
|
assert_eq!(avg_total.len(), avg_left.len());
|
|
assert_eq!(avg_total.mean(), avg_left.mean());
|
|
assert_eq!(avg_total.sample_variance(), avg_left.sample_variance());
|
|
}
|
|
}
|