# dsp.FFT

Discrete Fourier transform

## Description

The `dsp.FFT`

System object™ computes the discrete Fourier transform (DFT) of an input using fast Fourier
transform (FFT). The object uses one or more of the following fast Fourier transform (FFT)
algorithms depending on the complexity of the input and whether the output is in linear or
bit-reversed order:

The `dsp.FFT`

object and the `fft`

function both compute the discrete Fourier transform (DFT) using fast
Fourier transform (FFT). However, the object can process large streams of real-time data and
handle system states automatically. The function performs one-time computations on data that
is readily available and cannot handle system states. For a comparison between the two, see
System Objects vs MATLAB Functions.

To compute the DFT of an input:

Create the

`dsp.FFT`

object and set its properties.Call the object with arguments, as if it were a function.

To learn more about how System objects work, see What Are System Objects?

## Creation

### Description

returns a `ft`

= dsp.FFT`FFT`

object that computes the discrete Fourier transform (DFT)
of a real or complex *N*-D array input along the first dimension using
fast Fourier transform (FFT).

returns a `ft`

= dsp.FFT(`Name,Value`

)`FFT`

object with each specified property set to
the specified value. Enclose each property name in single quotes. Unspecified properties
have default values.

## Properties

## Usage

### Syntax

### Input Arguments

### Output Arguments

## Object Functions

To use an object function, specify the
System object as the first input argument. For
example, to release system resources of a System object named `obj`

, use
this syntax:

release(obj)

## Examples

## Algorithms

This object implements the algorithm, inputs, and outputs described on the FFT block reference page. The object properties correspond to the block parameters.

## References

[1] FFTW (`https://www.fftw.org`

)

[2] Frigo, M. and S. G. Johnson, “FFTW: An Adaptive Software
Architecture for the FFT,” *Proceedings of the International Conference on
Acoustics, Speech, and Signal Processing*, Vol. 3, 1998, pp. 1381-1384.

## Extended Capabilities

## Version History

**Introduced in R2012a**