# tensorplay.fft._frequency API

Source: https://www.tensorplay.cn/docs/api/tensorplay.fft._frequency.html

## Functions 4

[#](#api-tensorplay.fft._frequency.fftfreq)

### fftfreq

function[Full reference ↗](/docs/generated/tensorplay.fft._frequency.fftfreq.html)

```python
tensorplay.fft._frequency.fftfreq(n, d=1.0, *, out=None, dtype=None, layout=None, device=None, requires_grad=False)
```

DFT sample frequencies (cycles/unit): [0, 1, ..., (n-1)//2, -(n//2), ..., -1] / (n*d).

Parameters:

- n ([int](https://docs.python.org/3/builtins/functions.html#int)) – window length

- d ([float](https://docs.python.org/3/builtins/functions.html#float), optional) – sample spacing. Default: 1.0

- device (dtype / layout /) – of the result. Default: the default floating dtype, on the CPU

[#](#api-tensorplay.fft._frequency.fftshift)

### fftshift

function[Full reference ↗](/docs/generated/tensorplay.fft._frequency.fftshift.html)

```python
tensorplay.fft._frequency.fftshift(input, dim=None)
```

Re-orders an N-D FFT output so the zero-frequency term is centered.

Rolls by n // 2 along each (or the given) dimension(s).

[#](#api-tensorplay.fft._frequency.ifftshift)

### ifftshift

function[Full reference ↗](/docs/generated/tensorplay.fft._frequency.ifftshift.html)

```python
tensorplay.fft._frequency.ifftshift(input, dim=None)
```

Inverse of [fftshift()](/docs/generated/tensorplay.fft._frequency.fftshift.html#tensorplay.fft._frequency.fftshift); rolls by (n + 1) // 2 (odd-safe).

[#](#api-tensorplay.fft._frequency.rfftfreq)

### rfftfreq

function[Full reference ↗](/docs/generated/tensorplay.fft._frequency.rfftfreq.html)

```python
tensorplay.fft._frequency.rfftfreq(n, d=1.0, *, out=None, dtype=None, layout=None, device=None, requires_grad=False)
```

Sample frequencies for rfft()/one-sided transforms: [0..n//2] / (n*d).