Spectrum frequencies, returned as a column vector.

The length of the frequency vector is determined by
the `FrequencyRange`

and the FFT length.

If you set the `FrequencyRange`

to `'onesided'`

and the FFT length, `NFFT`

, is even,
the frequency vector is of length `NFFT/2+1`

, and covers the interval
`[0,SampleRate/2]`

.

If you set the `FrequencyRange`

to `'onesided'`

and `NFFT`

is odd, the frequency
vector is of length `(NFFT+1)/2`

and covers the interval
`[0,SampleRate/2]`

.

If you set the `FrequencyRange`

to `'twosided'`

, the frequency vector is of length
`NFFT`

and covers the interval `[0, SampleRate]`

.

If you set the `FrequencyRange`

to `'centered'`

, the frequency vector is of length
`NFFT`

and covers the range ```
[-SampleRate/2,
SampleRate/2]
```

and `[-SampleRate/2, SampleRate/2]`

for even
and odd length `NFFT`

, respectively.

**Data Types: **`single`

| `double`