Standard deviation helpers for f64 slices.

The functions are intentionally explicit and distinguish between population and sample standard deviation.

Examples

use use_standard_deviation::population_standard_deviation;

let values = [2.0, 4.0, 4.0, 4.0, 5.0, 5.0, 7.0, 9.0];
assert_eq!(population_standard_deviation(&values).unwrap(), 2.0);