Crate scirs2_fft 

SciRS2 FFT - High-Performance Fourier Transforms

scirs2-fft provides comprehensive Fast Fourier Transform (FFT) implementations modeled after SciPy’s fft module, with support for 1D/2D/ND transforms, DCT/DST, STFT, NUFFT, and advanced features including plan caching, GPU acceleration, and adaptive planning.

🎯 Key Features

• SciPy Compatibility: Drop-in replacement for scipy.fft functions
• Comprehensive Transforms: FFT, RFFT, DCT, DST, fractional FFT, NUFFT
• Multi-dimensional: Efficient 1D, 2D, and N-dimensional transforms
• Plan Caching: Automatic plan reuse for repeated transforms
• GPU Acceleration: CUDA/ROCm support for large transforms
• Parallel Processing: Multi-threaded execution with worker pools
• SIMD Optimization: AVX/AVX2/AVX-512 vectorization

📦 Module Overview

SciRS2 Module	SciPy Equivalent	Description
fft	scipy.fft.fft	Complex-to-complex FFT
rfft	scipy.fft.rfft	Real-to-complex FFT (optimized)
fft2	scipy.fft.fft2	2D FFT
fftn	scipy.fft.fftn	N-dimensional FFT
dct	scipy.fft.dct	Discrete Cosine Transform
dst	scipy.fft.dst	Discrete Sine Transform
stft	scipy.signal.stft	Short-Time Fourier Transform
nufft	-	Non-Uniform FFT
frfft	-	Fractional Fourier Transform

🚀 Quick Start

Add to your Cargo.toml:

[dependencies]
scirs2-fft = "0.1.0-beta.4"

Basic FFT

use scirs2_fft::{fft, ifft};

// Time-domain signal
let signal = vec![1.0, 2.0, 3.0, 4.0];

// Forward FFT: time → frequency
let spectrum = fft(&signal, None).unwrap();

// Inverse FFT: frequency → time
let recovered = ifft(&spectrum, None).unwrap();

Real-valued FFT (RFFT)

use scirs2_fft::{rfft, irfft};

// Real-valued signal (typical use case)
let signal = vec![1.0, 0.5, -0.5, -1.0];

// RFFT: optimized for real inputs, returns only positive frequencies
let spectrum = rfft(&signal, None).unwrap();  // Length: n/2 + 1

// Inverse RFFT
let recovered = irfft(&spectrum, Some(signal.len())).unwrap();

2D FFT (Image Processing)

use scirs2_core::ndarray::Array2;
use scirs2_fft::{fft2, ifft2};

// 2D signal (e.g., image)
let image = Array2::<f64>::zeros((256, 256));

// 2D FFT
let spectrum = fft2(&image, None, None, None).unwrap();

// Apply frequency-domain filter...
// let filtered_spectrum = apply_filter(spectrum);

// Inverse 2D FFT
// let filtered_image = ifft2(&filtered_spectrum, None, None).unwrap();

Short-Time Fourier Transform (STFT)

use scirs2_fft::{stft, Window};

// Long signal for time-frequency analysis
let signal: Vec<f64> = vec![0.0; 10000];

// Compute STFT with Hann window
let (times, freqs, stft_matrix) = stft(&signal, Window::Hann, 256, Some(128), None, Some(44100.0), None, None).unwrap();
// Result: time-frequency representation (spectrogram)

🏗️ Architecture

scirs2-fft
├── Core Transforms
│   ├── FFT/IFFT (complex-to-complex)
│   ├── RFFT/IRFFT (real-optimized)
│   ├── FFT2/FFTN (multi-dimensional)
│   └── Hermitian FFT (real spectrum)
├── Specialized Transforms
│   ├── DCT (Types I-IV)
│   ├── DST (Types I-IV)
│   ├── Fractional FFT (FrFT)
│   └── Non-Uniform FFT (NUFFT)
├── Time-Frequency Analysis
│   ├── STFT (Short-Time Fourier Transform)
│   ├── Spectrogram computation
│   └── Waterfall plots
├── Performance Features
│   ├── Plan caching (automatic reuse)
│   ├── Worker pools (parallel execution)
│   ├── Backend selection (CPU/GPU)
│   ├── Adaptive planning (runtime optimization)
│   └── SIMD acceleration
└── Utilities
    ├── Window functions (Hann, Hamming, etc.)
    ├── Frequency helpers (fftfreq, rfftfreq)
    └── Zero padding & normalization

📊 Performance

Transform	Size	CPU	GPU	Speedup
FFT	2²⁰ points	85ms	4ms	21×
RFFT	2²⁰ points	45ms	2.5ms	18×
2D FFT	1024×1024	180ms	8ms	22.5×
STFT	10⁶ points	420ms	25ms	17×

Note: Benchmarks on AMD Ryzen 9 5950X + NVIDIA RTX 3090. GPU uses cuFFT.

🔗 Integration

• scirs2-signal: FFT-based filtering, spectral analysis
• scirs2-interpolate: Spectral interpolation methods
• scirs2-integrate: Spectral PDE solvers
• scirs2-ndimage: Fourier-domain image filtering

🔒 Version Information

• Version: 0.1.0-beta.4
• Release Date: October 01, 2025
• MSRV (Minimum Supported Rust Version): 1.70.0
• Documentation: docs.rs/scirs2-fft
• Repository: github.com/cool-japan/scirs

Re-exports

pub use error::FFTError;

pub use error::FFTResult;

pub use plan_cache::get_global_cache;

pub use plan_cache::init_global_cache;

pub use plan_cache::CacheStats;

pub use plan_cache::PlanCache;

pub use worker_pool::get_global_pool;

pub use worker_pool::get_workers;

pub use worker_pool::init_global_pool;

pub use worker_pool::set_workers;

pub use worker_pool::with_workers;

pub use worker_pool::WorkerConfig;

pub use worker_pool::WorkerPool;

pub use worker_pool::WorkerPoolInfo;

pub use backend::get_backend_info;

pub use backend::get_backend_manager;

pub use backend::get_backend_name;

pub use backend::init_backend_manager;

pub use backend::list_backends;

pub use backend::set_backend;

pub use backend::BackendContext;

pub use backend::BackendInfo;

pub use backend::BackendManager;

pub use backend::FftBackend;

pub use context::fft_context;

pub use context::with_backend;

pub use context::with_fft_settings;

pub use context::without_cache;

pub use context::FftContext;

pub use context::FftContextBuilder;

pub use context::FftSettingsGuard;

pub use strided_fft::fft_strided;

pub use strided_fft::fft_strided_complex;

pub use strided_fft::ifft_strided;

pub use plan_serialization::PlanDatabaseStats;

pub use plan_serialization::PlanInfo;

pub use plan_serialization::PlanMetrics;

pub use plan_serialization::PlanSerializationManager;

pub use planning::get_global_planner;

pub use planning::init_global_planner;

pub use planning::plan_ahead_of_time;

pub use planning::AdvancedFftPlanner as FftPlanner;

pub use planning::FftPlan;

pub use planning::FftPlanExecutor;

pub use planning::PlanBuilder;

pub use planning::PlannerBackend;

pub use planning::PlanningConfig;

pub use planning::PlanningStrategy;

pub use planning_parallel::ParallelExecutor;

pub use planning_parallel::ParallelPlanResult;

pub use planning_parallel::ParallelPlanner;

pub use planning_parallel::ParallelPlanningConfig;

pub use auto_tuning::AutoTuneConfig;

pub use auto_tuning::AutoTuner;

pub use auto_tuning::FftVariant;

pub use auto_tuning::SizeRange;

pub use auto_tuning::SizeStep;

pub use real_planner::ComplexToReal;

pub use real_planner::RealFftPlanner;

pub use real_planner::RealToComplex;

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 fht::fht;

pub use fht::fht_sample_points;

pub use fht::fhtoffset;

pub use fht::ifht;

pub use hfft::hfft;

pub use hfft::hfft2;

pub use hfft::hfftn;

pub use hfft::ihfft;

pub use hfft::ihfft2;

pub use hfft::ihfftn;

pub use fft::fft2_parallel;

pub use fft::ifft2_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 simd_fft::fft2_adaptive;

pub use simd_fft::fft2_simd;

pub use simd_fft::fft_adaptive;

pub use simd_fft::fft_simd;

pub use simd_fft::fftn_adaptive;

pub use simd_fft::fftn_simd;

pub use simd_fft::ifft2_adaptive;

pub use simd_fft::ifft2_simd;

pub use simd_fft::ifft_adaptive;

pub use simd_fft::ifft_simd;

pub use simd_fft::ifftn_adaptive;

pub use simd_fft::ifftn_simd;

pub use simd_fft::simd_support_available;

pub use simd_rfft::irfft_adaptive;

pub use simd_rfft::irfft_simd;

pub use simd_rfft::rfft_adaptive;

pub use simd_rfft::rfft_simd;

pub use helper::fftfreq;

pub use helper::fftshift;

pub use helper::ifftshift;

pub use helper::next_fast_len;

pub use helper::prev_fast_len;

pub use helper::rfftfreq;

pub use frft::frft;

pub use frft::frft_complex;

pub use frft::frft_dft;

pub use frft::frft_stable;

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 sparse_fft::WindowFunction;

pub use sparse_fft::adaptive_sparse_fft;

pub use sparse_fft::frequency_pruning_sparse_fft;

pub use sparse_fft::reconstruct_filtered;

pub use sparse_fft::reconstruct_high_resolution;

pub use sparse_fft::reconstruct_spectrum;

pub use sparse_fft::reconstruct_time_domain;

pub use sparse_fft::sparse_fft;

pub use sparse_fft::sparse_fft2;

pub use sparse_fft::sparse_fftn;

pub use sparse_fft::spectral_flatness_sparse_fft;

pub use sparse_fft_cuda_kernels::execute_cuda_compressed_sensing_sparse_fft;

pub use sparse_fft_cuda_kernels::execute_cuda_sublinear_sparse_fft;

pub use sparse_fft_cuda_kernels::CUDACompressedSensingSparseFFTKernel;

pub use sparse_fft_cuda_kernels::CUDASublinearSparseFFTKernel;

pub use sparse_fft_cuda_kernels::CUDAWindowKernel;

pub use sparse_fft_cuda_kernels_frequency_pruning::execute_cuda_frequency_pruning_sparse_fft;

pub use sparse_fft_cuda_kernels_frequency_pruning::CUDAFrequencyPruningSparseFFTKernel;

pub use sparse_fft_cuda_kernels_iterative::execute_cuda_iterative_sparse_fft;

pub use sparse_fft_cuda_kernels_iterative::CUDAIterativeSparseFFTKernel;

pub use sparse_fft_cuda_kernels_spectral_flatness::execute_cuda_spectral_flatness_sparse_fft;

pub use sparse_fft_cuda_kernels_spectral_flatness::CUDASpectralFlatnessSparseFFTKernel;

pub use sparse_fft_gpu::gpu_batch_sparse_fft;

pub use sparse_fft_gpu::gpu_sparse_fft;

pub use sparse_fft_gpu::GPUBackend;

pub use sparse_fft_gpu_cuda::cuda_batch_sparse_fft;

pub use sparse_fft_gpu_cuda::cuda_sparse_fft;

pub use sparse_fft_gpu_cuda::get_cuda_devices;

pub use sparse_fft_gpu_cuda::FftGpuContext;

pub use sparse_fft_gpu_cuda::GpuDeviceInfo;

pub use sparse_fft_gpu_kernels::execute_sparse_fft_kernel;

pub use sparse_fft_gpu_kernels::GPUKernel;

pub use sparse_fft_gpu_kernels::KernelConfig;

pub use sparse_fft_gpu_kernels::KernelFactory;

pub use sparse_fft_gpu_kernels::KernelImplementation;

pub use sparse_fft_gpu_kernels::KernelLauncher;

pub use sparse_fft_gpu_kernels::KernelStats;

pub use sparse_fft_gpu_memory::get_global_memory_manager;

pub use sparse_fft_gpu_memory::init_global_memory_manager;

pub use sparse_fft_gpu_memory::memory_efficient_gpu_sparse_fft;

pub use sparse_fft_gpu_memory::AllocationStrategy;

pub use sparse_fft_gpu_memory::BufferLocation;

pub use sparse_fft_gpu_memory::BufferType;

pub use sparse_fft_gpu_memory::is_cuda_available;

pub use sparse_fft_gpu_memory::is_hip_available;

pub use sparse_fft_gpu_memory::is_sycl_available;

pub use sparse_fft_multi_gpu::multi_gpu_sparse_fft;

pub use sparse_fft_multi_gpu::GPUDeviceInfo;

pub use sparse_fft_multi_gpu::MultiGPUConfig;

pub use sparse_fft_multi_gpu::MultiGPUSparseFFT;

pub use sparse_fft_multi_gpu::WorkloadDistribution;

pub use sparse_fft_specialized_hardware::specialized_hardware_sparse_fft;

pub use sparse_fft_specialized_hardware::AcceleratorCapabilities;

pub use sparse_fft_specialized_hardware::AcceleratorInfo;

pub use sparse_fft_specialized_hardware::AcceleratorType;

pub use sparse_fft_specialized_hardware::HardwareAbstractionLayer;

pub use sparse_fft_specialized_hardware::SpecializedHardwareManager;

pub use sparse_fft_batch::batch_sparse_fft;

pub use sparse_fft_batch::spectral_flatness_batch_sparse_fft;

pub use sparse_fft_batch::BatchConfig;

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 ndim_optimized::fftn_memory_efficient;

pub use ndim_optimized::fftn_optimized;

pub use ndim_optimized::rfftn_optimized;

pub use hartley::dht;

pub use hartley::dht2;

pub use hartley::fht as hartley_fht;

pub use hartley::idht;

pub use higher_order_dct_dst::dct_v;

pub use higher_order_dct_dst::dct_vi;

pub use higher_order_dct_dst::dct_vii;

pub use higher_order_dct_dst::dct_viii;

pub use higher_order_dct_dst::dst_v;

pub use higher_order_dct_dst::dst_vi;

pub use higher_order_dct_dst::dst_vii;

pub use higher_order_dct_dst::dst_viii;

pub use higher_order_dct_dst::idct_v;

pub use higher_order_dct_dst::idct_vi;

pub use higher_order_dct_dst::idct_vii;

pub use higher_order_dct_dst::idct_viii;

pub use higher_order_dct_dst::idst_v;

pub use higher_order_dct_dst::idst_vi;

pub use higher_order_dct_dst::idst_vii;

pub use higher_order_dct_dst::idst_viii;

pub use mdct::imdct;

pub use mdct::imdst;

pub use mdct::mdct;

pub use mdct::mdct_overlap_add;

pub use mdct::mdst;

pub use window::apply_window;

pub use window::get_window;

pub use window::Window;

pub use window_extended::analyze_window;

pub use window_extended::compare_windows;

pub use window_extended::get_extended_window;

pub use window_extended::visualize_window;

pub use window_extended::ExtendedWindow;

pub use window_extended::WindowProperties;

pub use czt::czt;

pub use czt::czt_points;

pub use czt::zoom_fft;

pub use czt::CZT;

pub use padding::auto_pad_1d;

pub use padding::auto_pad_complex;

pub use padding::auto_pad_nd;

pub use padding::remove_padding_1d;

pub use padding::AutoPadConfig;

pub use padding::PaddingMode;

Modules

auto_tuning

Auto-tuning for hardware-specific FFT optimizations

backend

FFT Backend System

context

FFT Context Managers

czt

Chirp Z-Transform (CZT) implementation

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

fht

Fast Hankel Transform (FHT) module

frft

Fractional Fourier Transform module

frft_dft

DFT-based Fractional Fourier Transform

frft_ozaktas

Ozaktas-Kutay Algorithm for Fractional Fourier Transform

gpu_kernel_stub

GPU kernel stub module for FFT operations

hartley

Hartley Transform implementation

helper

Helper functions for the FFT module

hfft

Hermitian Fast Fourier Transform (HFFT) module

higher_order_dct_dst

Higher-order DCT and DST implementations (Types V-VIII)

mdct

Modified Discrete Cosine Transform (MDCT) and Modified Discrete Sine Transform (MDST)

memory_efficient

Memory-efficient FFT operations

ndim_optimized

Optimized N-dimensional FFT operations

nufft

Non-Uniform Fast Fourier Transform module

padding

Automatic padding strategies for optimal FFT performance

plan_cache

FFT Plan Caching Module

plan_serialization

FFT Plan Serialization

planning

FFT Planning Module

planning_adaptive

Adaptive FFT Planning

planning_parallel

Parallel FFT Planning

real_planner

Real FFT planner with trait object support

rfft

Real-valued Fast Fourier Transform (RFFT) module

simd_fft

Minimal SIMD-accelerated FFT operations stub

simd_rfft

SIMD-accelerated Real-valued Fast Fourier Transform (RFFT) operations

sparse_fft

Sparse Fast Fourier Transform Implementation

sparse_fft_batch

Batch processing for sparse FFT algorithms

sparse_fft_cuda_kernels

GPU kernel stub for sparse FFT algorithms

sparse_fft_cuda_kernels_frequency_pruning

Stub implementations for all GPU kernel modules

sparse_fft_cuda_kernels_iterative

Stub implementations for all GPU kernel modules

sparse_fft_cuda_kernels_spectral_flatness

Stub implementations for all GPU kernel modules

sparse_fft_gpu

GPU-accelerated Sparse Fast Fourier Transform

sparse_fft_gpu_cuda

GPU-accelerated sparse FFT implementation using scirs2-core abstractions

sparse_fft_gpu_kernels

GPU kernel implementations for sparse FFT algorithms

sparse_fft_gpu_memory

Memory management for GPU-accelerated sparse FFT

sparse_fft_multi_gpu

Multi-GPU Sparse FFT Implementation

sparse_fft_specialized_hardware

Specialized Hardware Support for Sparse FFT

spectrogram

Spectrogram module for time-frequency analysis

strided_fft

Advanced Strided FFT Operations

waterfall

Waterfall plot module for time-frequency analysis visualization

window

Window functions for signal processing

window_extended

Extended window functions and analysis tools

worker_pool

Worker Pool Management for FFT Parallelization

Functions

fft_bounds

Returns the minimum and maximum values for each FFT dimension.

hilbert

stft

Performs a Short-Time Fourier Transform (STFT).