Crate scirs2_fft

Fast Fourier Transform module

This module provides implementations of various Fast Fourier Transform algorithms, following SciPy’s fft module.

Overview

• Fast Fourier Transform (FFT) and inverse FFT for 1D, 2D, and N-dimensional arrays
• Real-to-complex and complex-to-real FFT optimized for real-valued data
• Discrete cosine transform (DCT) types I-IV and their inverses
• Discrete sine transform (DST) types I-IV and their inverses
• Fractional Fourier Transform (FrFT) for rotations in the time-frequency plane
• Non-Uniform Fast Fourier Transform (NUFFT) for non-uniformly sampled data
• Spectrogram and Short-Time Fourier Transform (STFT) for time-frequency analysis
• Waterfall plots for 3D visualization of time-frequency data
• Window functions for signal processing (Hann, Hamming, Blackman, etc.)
• Helper functions for frequency domain calculations and visualization

Implementation Notes

• Built on rustfft for efficient computation
• Provides proper zero padding and array reshaping
• Normalization options for compatibility with SciPy
• Support for ndarrays through ndarray integration

Examples

use scirs2_fft::{fft, ifft};
use num_complex::Complex64;

// Generate a simple signal
let signal = vec![1.0, 2.0, 3.0, 4.0];

// Compute FFT of the signal
let spectrum = fft(&signal, None).unwrap();

// Inverse FFT should recover the original signal
let recovered = ifft(&spectrum, None).unwrap();

// Check that the recovered signal matches the original
for (x, y) in signal.iter().zip(recovered.iter()) {
    assert!((x - y.re).abs() < 1e-10);
    assert!(y.im.abs() < 1e-10);
}

Re-exports

pub use error::FFTError;

pub use error::FFTResult;

pub use dct::dct;

pub use dct::dct2;

pub use dct::dctn;

pub use dct::idct;

pub use dct::idct2;

pub use dct::idctn;

pub use dct::DCTType;

pub use dst::dst;

pub use dst::dst2;

pub use dst::dstn;

pub use dst::idst;

pub use dst::idst2;

pub use dst::idstn;

pub use dst::DSTType;

pub use fft::fft;

pub use fft::fft2;

pub use fft::fftn;

pub use fft::ifft;

pub use fft::ifft2;

pub use fft::ifftn;

pub use fft::fft2_parallel;

pub use rfft::irfft;

pub use rfft::irfft2;

pub use rfft::irfftn;

pub use rfft::rfft;

pub use rfft::rfft2;

pub use rfft::rfftn;

pub use helper::fftfreq;

pub use helper::fftshift;

pub use helper::ifftshift;

pub use helper::rfftfreq;

pub use frft::frft;

pub use frft::frft_complex;

pub use spectrogram::spectrogram;

pub use spectrogram::spectrogram_normalized;

pub use spectrogram::stft as spectrogram_stft;

pub use waterfall::apply_colormap;

pub use waterfall::waterfall_3d;

pub use waterfall::waterfall_lines;

pub use waterfall::waterfall_mesh;

pub use waterfall::waterfall_mesh_colored;

pub use memory_efficient::fft2_efficient;

pub use memory_efficient::fft_inplace;

pub use memory_efficient::fft_streaming;

pub use memory_efficient::process_in_chunks;

pub use memory_efficient::FftMode;

pub use window::apply_window;

pub use window::get_window;

pub use window::Window;

Modules

dct

Discrete Cosine Transform (DCT) module

dst

Discrete Sine Transform (DST) module

error

Error types for the SciRS2 FFT module

fft

Fast Fourier Transform (FFT) module

frft

Fractional Fourier Transform module

helper

Helper functions for the FFT module

memory_efficient

Memory-efficient FFT operations

nufft

Non-Uniform Fast Fourier Transform module

rfft

Real-valued Fast Fourier Transform (RFFT) module

spectrogram

Spectrogram module for time-frequency analysis

waterfall

Waterfall plot module for time-frequency analysis visualization

window

Window functions for signal processing

Functions

fft_bounds

Returns the minimum and maximum values for each FFT dimension.

hilbert

Performs the Hilbert transform.

stft

Performs a Short-Time Fourier Transform (STFT).