FFT of vibration data

I have vibration data in time domain and i m unable to do FFT of this. please guide me

sampling rate 800 sample/sec

thanks

Answer 1

[Adeel Ashraf]

     Fs = 800; % sampling rate of 1000 Hz
     t = 0:1/Fs:1-1/Fs;
     x = ad2;
     xdft = fft(x);
     xdft = xdft(1:length(x)/2+1);
     DF = Fs/length(x); % frequency increment
     freqvec = 0:DF:Fs/2;
     plot(freqvec,abs(xdft))

I hope this can work