Function fft

contents/cooley_tukey/code/rust/fft.rs:11–22

(x: &[Complex<f64>])

// This is based on the Python and C implementations.

fn fft(x: &[Complex<f64>]) -> Vec<Complex<f64>> {
    let n = x.len();
    let mut new_x = x.to_vec();
    let mut y = vec![Complex::new(0.0_f64, 0.0_f64); n];

    let mut planner = FFTplanner::new(false);
    let this_fft = planner.plan_fft(n);
    this_fft.process(new_x.as_mut_slice(), y.as_mut_slice());

    // y.into_iter().map(|i| i / (n as f64).sqrt()).collect()
    y
}

fn dft(x: &[Complex<f64>]) -> Vec<Complex<f64>> {
    let n = x.len();