I want to obtain Power spectrum of the Voltage Timeseries of Vela Pulsar data given in picture below

How should i implement FFTW ?

I want to obtain Power spectrum of the Voltage Timeseries of Vela Pulsar data given in picture below

How should i implement FFTW ?

Does `DSP.welch_pgram`

or `DSP.periodogram`

help you?

No , i want to do it using FFTW but its documentation is not having examples. What should i do ?

I think FFTW.jl should have more elaborate documentation with example because fft is very useful .

How to find the DFT of a time series using FFTW:

```
using FFTW: fft, fftshift, fftfreq
data = ... # your data here
fs = ... # specify sampling frequency here
# frequencies where the DFT is evaluated:
f_range = fftshift(fftfreq(data, fs))
# DFT of data
data_f = fftshift(fft(data))
```

Using `fftshift`

is optional, but it will sort `f_range`

in ascending order, which is nice.

2 Likes

```
using DelimitedFiles,Plots ,PlutoUI,HypothesisTests,Statistics,FFTW
f=raw"/home/raman/Documents/VELA_Data.txt"
M = readdlm(f);
@bind data Slider(1000:1000:50000, default=10000)
M[1:data:end, 1]
g=fftshift(fft(M[1:data:end, 1]),125000)
```

```
g=fftshift(fft(M[1:data:end, 1]),125000)
```

is it correct ? Where 125000 is sampling frequency.