Struct chfft::CFft1D

pub struct CFft1D<T> { /* fields omitted */ }

Perform a complex-to-complex one-dimensional Fourier transform

When X is input array and Y is output array, the forward discrete Fourier transform of the one-dimensional array is

\[ \Large Y_k = \sum_{j=0}^{n-1} X_j e^{- \frac {2 \pi i j k}{n}} \]

also, the backward discrete Fourier transform of the one-dimensional array is

\[ \Large Y_k = \sum_{j=0}^{n-1} X_j e^{\frac {2 \pi i j k}{n}} \]

Example

extern crate chfft;
extern crate num_complex;
use num_complex::Complex;
use chfft::CFft1D;

fn main() {
    let input = [Complex::new(2.0, 0.0), Complex::new(1.0, 1.0),
                 Complex::new(0.0, 3.0), Complex::new(2.0, 4.0)];

    let mut fft = CFft1D::<f64>::with_len(input.len());

    let output = fft.forward(&input);

    println!("the transform of {:?} is {:?}", input, output);
}

Methods

impl<T: Float + FloatConst + NumAssign> CFft1D<T>

pub fn new() -> Self

Returns a instances to execute FFT

use chfft::CFft1D;
let mut fft = CFft1D::<f64>::new();

pub fn with_len(len: usize) -> Self

Returns a instances to execute length initialized FFT

use chfft::CFft1D;
let mut fft = CFft1D::<f64>::with_len(1024);

pub fn setup(&mut self, len: usize)

Reinitialize length

use chfft::CFft1D;
let mut fft = CFft1D::<f64>::with_len(1024);

// reinitialize
fft.setup(2048);

pub fn forward(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The 1 scaling factor forward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.forward(&input);

pub fn forward0(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The 1 scaling factor forward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.forward0(&input);

pub fn forwardu(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The \(\frac 1 {\sqrt n}\) scaling factor forward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.forwardu(&input);

pub fn forwardn(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The \(\frac 1 {n}\) scaling factor forward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.forwardn(&input);

pub fn backward(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The \(\frac 1 n\) scaling factor backward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.backward(&input);

pub fn backward0(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The 1 scaling factor backward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.backward0(&input);

pub fn backwardu(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The \(\frac 1 {\sqrt n}\) scaling factor backward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.backwardu(&input);

pub fn backwardn(&mut self, source: &[Complex<T>]) -> Vec<Complex<T>>

The \(\frac 1 n\) scaling factor backward transform

extern crate chfft;
extern crate num_complex;

let input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
let output = fft.backwardn(&input);

pub fn forward0i(&mut self, source: &mut [Complex<T>])

The 1 scaling factor and in-place forward transform

extern crate chfft;
extern crate num_complex;

let mut input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
fft.forward0i(&mut input);

pub fn backward0i(&mut self, source: &mut [Complex<T>])

The 1 scaling factor and in-place backward transform

extern crate chfft;
extern crate num_complex;

let mut input = [num_complex::Complex::new(2.0, 0.0), num_complex::Complex::new(1.0, 1.0),
             num_complex::Complex::new(0.0, 3.0), num_complex::Complex::new(2.0, 4.0)];

let mut fft = chfft::CFft1D::<f64>::with_len(input.len());
fft.backward0i(&mut input);

Trait Implementations