# vDSP.FFT A 1D single- and double-precision fast Fourier transform. ``` class FFT where T : vDSP_FourierTransformable ``` ## Topics ### Initializers [`init(log2n:radix:ofType:)`](/documentation/Accelerate/vDSP/FFT/init(log2n:radix:ofType:)) Initializes a new fast Fourier transform instance. ### Instance Methods [`forward(input:output:)`](/documentation/Accelerate/vDSP/FFT/forward(input:output:)) Computes an out-of-place forward fast Fourier transform. [`inverse(input:output:)`](/documentation/Accelerate/vDSP/FFT/inverse(input:output:)) Computes an out-of-place inverse fast Fourier transform. [`transform(input:output:direction:)`](/documentation/Accelerate/vDSP/FFT/transform(input:output:direction:)) Computes an out-of-place fast Fourier transform. ### Variables [`FFT_FORWARD`](/documentation/Accelerate/FFT_FORWARD) Forward FFT. [`FFT_INVERSE`](/documentation/Accelerate/FFT_INVERSE) Inverse FFT. [`FFT_RADIX2`](/documentation/Accelerate/FFT_RADIX2) [`FFT_RADIX3`](/documentation/Accelerate/FFT_RADIX3) [`FFT_RADIX5`](/documentation/Accelerate/FFT_RADIX5) [`kFFTDirection_Forward`](/documentation/Accelerate/kFFTDirection_Forward) [`kFFTDirection_Inverse`](/documentation/Accelerate/kFFTDirection_Inverse) [`kFFTRadix2`](/documentation/Accelerate/kFFTRadix2) [`kFFTRadix3`](/documentation/Accelerate/kFFTRadix3) [`kFFTRadix5`](/documentation/Accelerate/kFFTRadix5) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)