,

Computes the Discrete Fourier Transform (DFT) of an array with a fast algorithm, the “Fast Fourier Transform” (FFT). Wrapper of stats::fft with an extra argument similar to python's numpy.fft.fft.

`sig_fft(x, n = NULL)`

- x
A vector

- n
Length of the transformed axis of the output. If

`n`

is smaller than the length of the input, the input is cropped. If it is larger, the input is padded with zeros. If n is not given, the length of the input along the axis specified by axis is used.

```
a <- c(0, 4, 0, 0)
sig_fft(a)
#> [1] 4+0i 0-4i -4+0i 0+4i
```