Function harmonicity 

pub fn harmonicity(
    magnitude_spectrum: &[f64],
    normalize_by_total_energy: bool,
) -> f64

Calculates the harmonicity of a magnitude pectrum (determines how harmonic a signal is). (Eyben, 43-44)

Example

use aus::{spectrum, analysis};
let fft_size = 2048;
let audio = aus::read("myfile.wav").unwrap();
let imaginary_spectrum = spectrum::rfft(&audio.samples[0][..fft_size], fft_size);
let (magnitude_spectrum, phase_spectrum) = spectrum::complex_to_polar_rfft(&imaginary_spectrum);
let h_index = analysis::harmonicity(&magnitude_spectrum, true);