A high-performance FFT library for Go, ported from RustFFT.

Status: v0.5.0 - 100% Algorithm Parity Achieved!

• 100% scalar algorithm parity with RustFFT (NEW in v0.5.0!)
• RadixN algorithm for multi-factor composites (NEW in v0.5.0!)
• Rader's algorithm for optimized primes
• ANY size is O(n log n) via Bluestein's
• 28 total algorithms (20 butterflies + Radix-4 + RadixN + Rader's + more)
• Zero allocations with scratch buffer reuse
• Thread-safe - concurrent usage supported
• SIMD support (future enhancement for 2-8x speedup)

package main

import (
    "github.com/10d9e/gofft"
)

func main() {
    // Create a planner
    planner := gofft.NewPlanner()
    
    // Plan a forward FFT of size 1024
    fft := planner.PlanForward(1024)
    
    // Create and process data
    buffer := make([]complex128, 1024)
    // ... fill buffer with data ...
    fft.Process(buffer)
}

v0.5.0: 100% ALGORITHM PARITY!

• RadixN: Optimizes multi-factor composites (60, 120, 84, ...)
• Complete scalar algorithm set from RustFFT
• 28 algorithms, 320+ tests, all passing!

v0.4.0: Rader's algorithm for primes
v0.3.2: Bluestein's for ANY size

Pure Go (no SIMD) on Apple M3 Pro:

• Size 1024: 12 μs (0 allocs)
• Size 4096: 59 μs (0 allocs)
• Prime 1009: O(n log n) via Bluestein's ✨
• Size 1000: O(n log n) via Bluestein's ✨

2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, ...

2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 16, 17, 19, 23, 24, 27, 29, 31, 32

6, 10, 12, 14, 15, 18, 20, 21, 24, 28, 30, 36, 40, 42, 48, 54, 56, 60, 72, 80, 84, 90, 96, 100, 120, ...

All primes from 3 to 97 use Rader's algorithm

Large primes, sizes with prime factors >7 - ALL O(n log n)!

# Build
go build ./...

# Run tests (all passing!)
go test -v

# Run benchmarks
go test -bench=. -benchmem

# Try the examples
go run cmd/example/main.go

• 100% ALGORITHM PARITY - Complete RustFFT scalar port!
• RadixN Algorithm: Multi-factor decomposition for composites
• 320+ tests passing (up from 256)
• 28 algorithms implemented
• Optimized for ALL size categories

• V0.5.0_100PERCENT_COMPLETE.md - 100% parity milestone! 🏆
• V0.4.0_RELEASE_NOTES.md - v0.4.0 release notes
• API_REFERENCE.md - Detailed API documentation

100% SCALAR ALGORITHM PARITY with RustFFT!
O(n log n) for ALL sizes
320+ tests passing (100% success rate)
28 algorithms - complete scalar algorithm set