How to increase amplitude of a peak in fft in MATLAB?

Hello Everybody,

I am writing following code to plot fft in matlab from the ascii values. But i am getting less amplitude of the peak(as i get from the other software). How can i increase the amplitude? or is it a problem of windowing in fft? please suggest..am i doing right or wrong?

the code is following..

I = load('data1.asc');

for i = 1:2048

x = I(:,2);

end

plot(x)

Fs = 40000;

T = 1/Fs;

L = 2000;

NFFT = 2^nextpow2(L);

Y = abs(fft(x,NFFT))/L;

f = Fs/2*linspace(0,1,NFFT/2+1);

figure, plot(f,2*abs(Y(1:NFFT/2+1)))

xlabel('Frequency (Hz)')

ylabel('Magnitude')

Answer 1

[Dishant Arora]

In the other software you might be plotting fft against indices and here you are doing it differently i.e fft vs frequency samples. you can try below mentioned code to get the desired result.

Y = abs(fft(x));
plot(y)

[Dishant Arora]

Also you can omit the for loop, simply use:

x = I(:,2);

and there's no need for NFFT as your data length is already in powers of 2.