easyfft

A Rust library crate providing an [FFT] API for arrays and slices. This crate wraps the [rustfft] and [realfft] crates that does the heavy lifting behind the scenes.

Advantages

• If it compiles, your code won't panic™ in this library[^panic]
• No [Result] return type for you to worry about
• Ergonomic API

Current limitations

• The realfft feature requires the nightly compiler because it depends on the [genericconstexprs] feature

Complex Array Example:

```rust use approx::assertulpseq; use easyfft::Complex; use easyfft::Fft; use easyfft::Ifft;

// Define a real-valued signal let realsignal = [1.0f64; 10];

// Call .fft() on the signal to obtain it's discrete fourier transform let realsignaldft: [Complex; 10] = real_signal.fft();

// Call .ifft() on the frequency domain signal to obtain it's inverse let realsignaldftidft: [Complex; 10] = realsignal_dft.ifft();

// Verify the resulting signal is a scaled value of the original signal for (original, manipulated) in realsignal.iter().zip(realsignaldftidft) { assertulpseq!(manipulated.re, original * realsignal.len() as f64); assertulps_eq!(manipulated.im, 0.0); }

// Define a complex-valued signal let complexsignal = [Complex::new(1.0f64, 0.0); 10];

// Call .fft() on the signal to obtain it's discrete fourier transform let complexsignaldft: [Complex; 10] = complex_signal.fft();

// Call .ifft() on the frequency domain signal to obtain it's inverse let complexsignaldftidft: [Complex; 10] = complexsignal_dft.ifft();

// Verify the resulting signal is a scaled value of the original signal for (original, manipulated) in complexsignal.iter().zip(complexsignaldftidft) { assertulpseq!(manipulated.re, original.re * complexsignal.len() as f64); assertulpseq!(manipulated.im, original.im * complexsignal.len() as f64); } ```

Real Signal Example:

See [realfft module] level documentation.

Footnotes

Currently you can create a RealDft struct and mutate it using the DerefMut trait in a way that the real_ifft method will cause a panic. This should be fixable in a future patch release currently pending implementation details. There could be other bugs in this crate or it's dependencies that may cause a panic, but in theory all the runtime panics have been moved to compile time errors.