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Verify distribution uniformity/Chi-squared test: Difference between revisions
Verify distribution uniformity/Chi-squared test (view source)
Revision as of 13:31, 11 April 2021
, 3 years agoAdd Rust implementation
(Add Rust implementation) |
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Line 1,399:
probability: -0.0000
uniform? No
</pre>
=={{header|Rust}}==
<lang rust>
use statrs::function::gamma::gamma_li;
fn chi_distance(dataset: &[u32]) -> f64 {
let expected = f64::from(dataset.iter().sum::<u32>()) / dataset.len() as f64;
dataset
.iter()
.fold(0., |acc, &elt| acc + (elt as f64 - expected).powf(2.))
/ expected
}
fn chi2_probability(dof: f64, distance: f64) -> f64 {
1. - gamma_li(dof * 0.5, distance * 0.5)
}
fn chi2_uniform(dataset: &[u32], significance: f64) -> bool {
let d = chi_distance(&dataset);
chi2_probability(dataset.len() as f64 - 1., d) > significance
}
fn main() {
let dsets = vec![
vec![199809, 200665, 199607, 200270, 199649],
vec![522573, 244456, 139979, 71531, 21461],
];
for ds in dsets {
println!("Data set: {:?}", ds);
let d = chi_distance(&ds);
print!("Distance: {:.6} ", d);
print!(
"Chi2 probability: {:.6} ",
chi2_probability(ds.len() as f64 - 1., d)
);
print!("Uniform? {}\n", chi2_uniform(&ds, 0.05));
}
}
</lang>
{{out}}
<pre>
Data set: [199809, 200665, 199607, 200270, 199649]
Distance: 4.146280 Chi2 probability: 0.386571 Uniform? true
Data set: [522573, 244456, 139979, 71531, 21461]
Distance: 790063.275940 Chi2 probability: 0.000000 Uniform? false
</pre>
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