How we can calculate Power spectrum of EEG signal?

Dear all . I want to calculate power spectrum of single channel eeg . I have coded following but it gives error

??? Subscript indices must either be real positive integers or logicals.

Error in ==> modemotion at 17
plot(ff,pp(0:63)); ylabel('power spectrum
density');xlabel('frequency');title('signal power spectrum');

Please give me how i can short out this.

%%%%%Program to calculate the power spectrum of EEG signal%%%%
clear all;
clc;
data=xlsread('C:\Users\SID\Desktop\emotion regulation post2\emotion\shim1.xlsx');
figure(1); xlabel('sample'); ylabel('magnitude'); plot(data);
legend('14 channel plot of subject1 BASELINE');
data= data';
value1=data(1,:);
chan1= value1-mean(value1);
fs=128;d=1/fs;
t=[0:length(chan1)-1]*d;
figure(2);
plot(chan1);title('original signal');
fs=fft(chan1,128);
pp=fs.*conj(fs)/128;
ff=(0:63)/128/d;
figure(3);
plot(ff,pp(0:63)); ylabel('power spectrum density');xlabel('frequency');title('signal power spectrum');

[Star Strider]

 %%%%%Program to calculate the power spectrum of EEG signal%%%%
 clear all; 
 clc; 

data=xlsread('C:\Users\SID\Desktop\emotion regulation post2\emotion\shim1.xlsx'); 

figure(1); 
xlabel('sample'); 
ylabel('magnitude'); 
plot(data); 
legend('14 channel plot of subject1 BASELINE'); 

data= data'; 
value1=data(1,:); 
chan1= value1-mean(value1); 
fs=128;
d=1/fs; 
t=[0:length(chan1)-1]*d; 

figure(2); 
plot(chan1);
title('original signal'); 

fs=fft(chan1,128); 
pp=fs.*conj(fs)/128; 
ff=(0:63)/128/d; 

figure(3); 
plot(ff,pp(0:63)); 
ylabel('power spectrum density');
xlabel('frequency');
title('signal power spectrum');

[shivani puranik]

but the error remains the same

Answer 1

[Krishnapriya V B]

%%%%%Program to calculate the power spectrum of EEG signal%%%%

clear all;

clc;

data=xlsread('C:\Users\SID\Desktop\emotion regulation post2\emotion\shim1.xlsx');

figure(1); xlabel('sample'); ylabel('magnitude'); plot(data);

legend('14 channel plot of subject1 BASELINE');

data= data';

value1=data(1,:);

chan1= value1-mean(value1);

fs=128;d=1/fs;

t=[0:length(chan1)-1]*d;

figure(2);

plot(chan1);title('original signal');

fs=fft(chan1,128);

pp=fs.*conj(fs)/128;

ff=(0:63)/128/d;

figure(3);

plot(ff,pp(0:63)); ylabel('power spectrum density');xlabel('frequency');title('signal power spectrum');

[Ashish Tiwari]

plot(ff,pp( :,1:64)); ylabel('power spectrum density');xlabel('frequency');title('signal power spectrum');

do the minor change in your code and you will get your result just look at the last line and change that to this--->>"plot(ff,pp( : ,1:64)); .indexing was not done properly in your mentioned code

[Keerthivasan M]

which date to be load

Answer 2

[Ashish Tiwari]

plot(ff,pp( :,1:64)); ylabel('power spectrum density');xlabel('frequency');title('signal power spectrum');

do the minor change in your code and you will get your result just look at the last line and change that to this--->>"plot(ff,pp( : ,1:64)); .indexing was not done properly in your mentioned code