Note: This page has been translated by MathWorks. Click here to see

To view all translated materials including this page, select Country from the country navigator on the bottom of this page.

To view all translated materials including this page, select Country from the country navigator on the bottom of this page.

Inverse fast Fourier transform

`X = ifft(Y)`

`X = ifft(Y,n)`

`X = ifft(Y,n,dim)`

`X = ifft(___,symflag)`

`X = ifft(`

computes
the inverse discrete Fourier transform of `Y`

)`Y`

using
a fast Fourier transform algorithm. `X`

is the same
size as `Y`

.

If

`Y`

is a vector, then`ifft(Y)`

returns the inverse transform of the vector.If

`Y`

is a matrix, then`ifft(Y)`

returns the inverse transform of each column of the matrix.If

`Y`

is a multidimensional array, then`ifft(Y)`

treats the values along the first dimension whose size does not equal 1 as vectors and returns the inverse transform of each vector.

The

`ifft`

function tests whether the vectors in`Y`

are conjugate symmetric. A vector`v`

is conjugate symmetric when it equals`conj(v([1,end:-1:2]))`

. If the vectors in`Y`

are conjugate symmetric, then the inverse transform computation is faster and the output is real.