Struct rustfft::algorithm::GoodThomasAlgorithmSmall [−][src]
pub struct GoodThomasAlgorithmSmall<T> { /* fields omitted */ }
Implementation of the Good-Thomas Algorithm, specialized for smaller input sizes
This algorithm factors a size n FFT into n1 * n2, where GCD(n1, n2) == 1
Conceptually, this algorithm is very similar to MixedRadix, except because GCD(n1, n2) == 1 we can do some number theory trickery to reduce the number of floating point operations. It typically performs better than MixedRadixSmall, especially at the smallest sizes.
// Computes a forward FFT of size 56 using GoodThomasAlgorithmSmall use std::sync::Arc; use rustfft::algorithm::GoodThomasAlgorithmSmall; use rustfft::algorithm::butterflies::{Butterfly7, Butterfly8}; use rustfft::{Fft, FftDirection}; use rustfft::num_complex::Complex; let mut buffer = vec![Complex{ re: 0.0f32, im: 0.0f32 }; 56]; // we need to find an n1 and n2 such that n1 * n2 == 56 and GCD(n1, n2) == 1 // n1 = 7 and n2 = 8 satisfies this let inner_fft_n1 = Arc::new(Butterfly7::new(FftDirection::Forward)); let inner_fft_n2 = Arc::new(Butterfly8::new(FftDirection::Forward)); // the good-thomas FFT length will be inner_fft_n1.len() * inner_fft_n2.len() = 56 let fft = GoodThomasAlgorithmSmall::new(inner_fft_n1, inner_fft_n2); fft.process(&mut buffer);
Implementations
impl<T: FftNum> GoodThomasAlgorithmSmall<T>
[src]
impl<T: FftNum> GoodThomasAlgorithmSmall<T>
[src]Trait Implementations
impl<T: FftNum> Direction for GoodThomasAlgorithmSmall<T>
[src]
impl<T: FftNum> Direction for GoodThomasAlgorithmSmall<T>
[src]fn fft_direction(&self) -> FftDirection
[src]
fn fft_direction(&self) -> FftDirection
[src]Returns FftDirection::Forward if this instance computes forward FFTs, or FftDirection::Inverse for inverse FFTs
impl<T: FftNum> Fft<T> for GoodThomasAlgorithmSmall<T>
[src]
impl<T: FftNum> Fft<T> for GoodThomasAlgorithmSmall<T>
[src]fn process_outofplace_with_scratch(
&self,
input: &mut [Complex<T>],
output: &mut [Complex<T>],
scratch: &mut [Complex<T>]
)
[src]
fn process_outofplace_with_scratch(
&self,
input: &mut [Complex<T>],
output: &mut [Complex<T>],
scratch: &mut [Complex<T>]
)
[src]Divides input
and output
into chunks of size self.len()
, and computes a FFT on each chunk. Read more
fn process_with_scratch(
&self,
buffer: &mut [Complex<T>],
scratch: &mut [Complex<T>]
)
[src]
fn process_with_scratch(
&self,
buffer: &mut [Complex<T>],
scratch: &mut [Complex<T>]
)
[src]Divides buffer
into chunks of size self.len()
, and computes a FFT on each chunk. Read more
fn get_inplace_scratch_len(&self) -> usize
[src]
fn get_inplace_scratch_len(&self) -> usize
[src]Returns the size of the scratch buffer required by process_with_scratch
Read more
fn get_outofplace_scratch_len(&self) -> usize
[src]
fn get_outofplace_scratch_len(&self) -> usize
[src]Returns the size of the scratch buffer required by process_outofplace_with_scratch
Read more