i need to plot the EEG in matlab.. i have downloaded the data base which is in .txt format. bt i am unable to plot it.. plz help

x=load('F001.txt'); 
y=fft(x)
PS=abs(y).^2;
N=length(x);
fs=1000; 
freq=(1:N/2)*fs/N;
plot(freq,PS)

this is not working,... an error is reported

Error using plot Vectors must be the same lengths.

Error in PLOT (line 7) plot(freq,PS)

Answer 1

[Azzi Abdelmalek]

Look at freq=(1:N/2)*fs/N ,its length is different from PS length

[joyaprita]

how to correct the prob?

[joyaprita]

whats the right code?

[Azzi Abdelmalek]

What does fs represent?

[Azzi Abdelmalek]

x=load('F001.txt'); 
y=fft(x)
PS=abs(y).^2;
N=length(x);
fs=1000; 
freq=(0:N-1)*fs/N;
plot(freq,PS)

If you want a symetric plot for frequencies: [-freq,freq]

freq=(0:ceil(N/2)-1)*fs/N;
PS=PS(1:numel(freq));
plot([-freq freq],[fliplr(PS) PS])

[joyaprita]

thank you it worked :)