Trait statrs::statistics::Variance [−] [src]

pub trait Variance<T>: Mean<T> {
    fn variance(&self) -> T;
    fn std_dev(&self) -> T;
}

The Variance trait specifies that an object has a closed form solution for its variance(s). Requires Mean since a closed form solution to variance by definition requires a closed form mean.

Required Methods

Returns the variance. May panic depending on the implementor.

Examples

use statrs::statistics::Variance;
use statrs::distribution::Uniform;

let n = Uniform::new(0.0, 1.0).unwrap();
assert_eq!(1.0 / 12.0, n.variance());

Returns the standard deviation. May panic depending on the implementor.

Examples

use statrs::statistics::Variance;
use statrs::distribution::Uniform;

let n = Uniform::new(0.0, 1.0).unwrap();
assert_eq!((1f64 / 12f64).sqrt(), n.std_dev());

Implementors