gauravnanda18
Newbie level 1
what I have to do is to calculate the noise in a signal and see how it depends on the frequency spectrum. I am trying to calculate PSD of a signal but everytime, I get an error saying "vectors must be the same lengths". I am not able to find a solution.
Here is command which I'm using. please let me know if there is some problem with the command.
I imported the excel file as vectors.
x=time; %time vector in excel file
y=current; %current vector in excel file
plot(x,y); % plot current-time graph
xlabel('time(s)');
ylabel('current(A)');
Fs=50; %sampling frequency
T=1/Fs; %sampling time
L=length; %length of the signal
L1= x/T;
t=(0:L-1)*T; time vector
%%%calculate the mean current
Iavg=mean(L);
%calculate the FFT
NFFT=2^nextpow2(L); %next power of 2 from length y
% calculate and plot PSD of conditioning mode
Nc=abs(fft((y-mean),NFFT)).^2./NFFT; % Nc is power spectral density
Nc = Nc(1:513);
Nc(2:end-1) = 2*Nc(2:end-1);
fc=Fs/2*linspace(0,1,NFFT/2+1);%frequency
plot(fc,Nc)
ERROR MESSAGE WHICH I GET IS "INDEX EXCEEDS MATRIX DIMENSIONS"
Here is command which I'm using. please let me know if there is some problem with the command.
I imported the excel file as vectors.
x=time; %time vector in excel file
y=current; %current vector in excel file
plot(x,y); % plot current-time graph
xlabel('time(s)');
ylabel('current(A)');
Fs=50; %sampling frequency
T=1/Fs; %sampling time
L=length; %length of the signal
L1= x/T;
t=(0:L-1)*T; time vector
%%%calculate the mean current
Iavg=mean(L);
%calculate the FFT
NFFT=2^nextpow2(L); %next power of 2 from length y
% calculate and plot PSD of conditioning mode
Nc=abs(fft((y-mean),NFFT)).^2./NFFT; % Nc is power spectral density
Nc = Nc(1:513);
Nc(2:end-1) = 2*Nc(2:end-1);
fc=Fs/2*linspace(0,1,NFFT/2+1);%frequency
plot(fc,Nc)
ERROR MESSAGE WHICH I GET IS "INDEX EXCEEDS MATRIX DIMENSIONS"