# ifftshift

Shift frequency spectrum related vectors to uncenter the dc element to the first position.

## Syntax

y = ifftshift(x)

y = ifftshift(x,dim)

## Inputs

`x`- The frequency spectrum related vectors to shift.
`dim`- The dimension on which to operate.

## Outputs

`y`- The shifted vectors.

## Example

Show that ifftshift reverses the output of fftshift.

```
x = fftshift([1:8])
y = ifftshift(x)
x = [Matrix] 1 x 8
5 6 7 8 1 2 3 4
y = [Matrix] 1 x 8
1 2 3 4 5 6 7 8
```

If `x(5)`is the location of the dc frequency and`x(1)`is the location of the negative Nyquist frequency, then`y(1)`is the location of the dc frequency and`y(5)`is the location of Nyquist frequency.## Comments

After ifftshift, if a vector has an even number of samples the Nyquist frequency of the input will become centered in the output vector.