Add test comparing to streaming-stats

This commit is contained in:
Vinzent Steinberg 2017-05-05 16:40:23 +02:00
parent a5aa7df51d
commit 53b44d1a13
3 changed files with 41 additions and 3 deletions

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@ -6,6 +6,7 @@ extern crate stats;
use bencher::Bencher;
/// Create a random vector by sampling from a normal distribution.
fn initialize_vec() -> Vec<f64> {
use rand::distributions::{Normal, IndependentSample};
use rand::{XorShiftRng, SeedableRng};

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@ -140,13 +140,15 @@ impl core::iter::FromIterator<f64> for Average {
///
/// On panic, this macro will print the values of the expressions with their
/// debug representations.
#[macro_export]
macro_rules! assert_almost_eq {
($a:expr, $b:expr, $prec:expr) => (
if ($a - $b).abs() > $prec {
let diff = ($a - $b).abs();
if diff > $prec {
panic!(format!(
"assertion failed: `abs(left - right) < {:e}`, \
"assertion failed: `abs(left - right) = {:.1e} < {:e}`, \
(left: `{}`, right: `{}`)",
$prec, $a, $b));
diff, $prec, $a, $b));
}
);
}

35
tests/average.rs Normal file
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@ -0,0 +1,35 @@
#[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::Average = 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-16);
}
#[test]
fn average_vs_streaming_stats_large() {
let values = initialize_vec(1_000_000);
let a: average::Average = 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);
}