Struct MixedRadix 

pub struct MixedRadix<T> {
    twiddles: Box<[Complex<T>]>,
    width_size_fft: Arc<dyn Fft<T>>,
    width: usize,
    height_size_fft: Arc<dyn Fft<T>>,
    height: usize,
    inplace_scratch_len: usize,
    outofplace_scratch_len: usize,
    immut_scratch_len: usize,
    direction: FftDirection,
}

Implementation of the Mixed-Radix FFT algorithm

This algorithm factors a size n FFT into n1 * n2, computes several inner FFTs of size n1 and n2, then combines the results to get the final answer

// Computes a forward FFT of size 1200, using the Mixed-Radix Algorithm
use rustfft::algorithm::MixedRadix;
use rustfft::{Fft, FftPlanner};
use rustfft::num_complex::Complex;

let mut buffer = vec![Complex{ re: 0.0f32, im: 0.0f32 }; 1200];

// we need to find an n1 and n2 such that n1 * n2 == 1200
// n1 = 30 and n2 = 40 satisfies this
let mut planner = FftPlanner::new();
let inner_fft_n1 = planner.plan_fft_forward(30);
let inner_fft_n2 = planner.plan_fft_forward(40);

// the mixed radix FFT length will be inner_fft_n1.len() * inner_fft_n2.len() = 1200
let fft = MixedRadix::new(inner_fft_n1, inner_fft_n2);
fft.process(&mut buffer);

Fields

twiddles: Box<[Complex<T>]>

width_size_fft: Arc<dyn Fft<T>>

width: usize

height_size_fft: Arc<dyn Fft<T>>

height: usize

inplace_scratch_len: usize

outofplace_scratch_len: usize

immut_scratch_len: usize

direction: FftDirection

Implementations

impl<T: FftNum> MixedRadix<T>

pub fn new(width_fft: Arc<dyn Fft<T>>, height_fft: Arc<dyn Fft<T>>) -> Self

Creates a FFT instance which will process inputs/outputs of size width_fft.len() * height_fft.len()

fn perform_fft_inplace( &self, buffer: &mut [Complex<T>], scratch: &mut [Complex<T>], )

fn perform_fft_immut( &self, input: &[Complex<T>], output: &mut [Complex<T>], scratch_raw: &mut [Complex<T>], )

fn perform_fft_out_of_place( &self, input: &mut [Complex<T>], output: &mut [Complex<T>], scratch: &mut [Complex<T>], )

Trait Implementations

impl<T: FftNum> Direction for MixedRadix<T>

fn fft_direction(&self) -> FftDirection

Returns FftDirection::Forward if this instance computes forward FFTs, or FftDirection::Inverse for inverse FFTs

impl<T: FftNum> Fft<T> for MixedRadix<T>

fn process_immutable_with_scratch( &self, input: &[Complex<T>], output: &mut [Complex<T>], scratch: &mut [Complex<T>], )

Divides input and output into chunks of self.len(), and computes a FFT on each chunk while keeping input untouched.

fn process_outofplace_with_scratch( &self, input: &mut [Complex<T>], output: &mut [Complex<T>], scratch: &mut [Complex<T>], )

Divides input and output into chunks of size self.len(), and computes a FFT on each chunk.

fn process_with_scratch( &self, buffer: &mut [Complex<T>], scratch: &mut [Complex<T>], )

Divides buffer into chunks of size self.len(), and computes a FFT on each chunk.

fn get_inplace_scratch_len(&self) -> usize

Returns the size of the scratch buffer required by process_with_scratch

fn get_outofplace_scratch_len(&self) -> usize

Returns the size of the scratch buffer required by process_outofplace_with_scratch

fn get_immutable_scratch_len(&self) -> usize

Returns the size of the scratch buffer required by process_immutable_with_scratch

fn process(&self, buffer: &mut [Complex<T>])

Computes a FFT in-place.

impl<T: FftNum> Length for MixedRadix<T>

fn len(&self) -> usize

The FFT size that this algorithm can process