Table of Contents

1. Installation
2. Notes
3. Reference
   1. Public methods
      1. FFT.fft(data: Array<float>) -> Array<Complex>
      2. FFT.ifft(data: Array<Complex>) -> Array<Complex>
      3. FFT.reals(data: Array<Complex>) -> Array<float>
      4. FFT.imags(data: Array<Complex>) -> Array<float>
      5. FFT.ensure_complex(data: Array<MaybeComplex>) -> Array<Complex>
   2. Internal methods
      1. FFT.conjugate(amplitudes: Array<Complex>) -> Array<Complex>
      2. FFT.keyed(data: Array<Dictionary>, key: String) -> Data<Any>

Fast Fourier Transform in GDScript

Mostly modified from The javascript FFT on rosetta code.

Installation

1. Install addon
2. Enable plugin from the project-settings

The singleton FFT is autoloaded at your project start, so you can simply call the static functionality as shown below.

    var result = FFT.fft([1, 1, 1, 1, 0, 0, 0, 0])
    result = FFT.fft(result)

    for item in result:
        item.log()

Notes

This is an in-place modification for speed, so if you want to ensure functional purity you can duplicate your data array before passing it into the fft or ifft functionality. The data array is also returned.

    var my_arr = [1, 1, 1, 1, 0, 0, 0, 0]
    var result = FFT.fft(my_arr.duplicate(true))
    # my_arr remains unchanged

Reference

Public methods

FFT.fft(data: Array<float>) -> Array<Complex>

Forward transformation from data-space into fourier-space.

FFT.ifft(data: Array<Complex>) -> Array<Complex>

Reverse transformation from fourier-space into data-space.

FFT.reals(data: Array<Complex>) -> Array<float>

Returns the real part of each data point.

FFT.imags(data: Array<Complex>) -> Array<float>

Returns the imaginary part of each data point.

FFT.ensure_complex(data: Array<MaybeComplex>) -> Array<Complex>

Ensure that all data items in the array are Complex numbers.

Internal methods

FFT.conjugate(amplitudes: Array<Complex>) -> Array<Complex>

Flips the sign of each amplitude

FFT.keyed(data: Array<Dictionary>, key: String) -> Data<Any>

Returns data[idx][key] for each index.