Error using stem X must be same length as Y.

fs = 100000; %sampling frequency 
Ts = 1/fs;
Tstart = 22.7; % change to 22.6 for 2.4s time window
N = 2500001;%number of sample for fitting
T = N*Ts;
Electrical_Output_Torque = out.ScopeData12(:,2);
currenta=out.ScopeData7(:,2);
currentb=out.ScopeData7(:,3);
currentc=out.ScopeData7(:,4);
t1 = (1:length(currenta))*Ts;
figure(1)
plot(t1,currenta,'r')
title('Current Measurement in Time Domain');
xlabel('Time [s]');
ylabel('Current [A]');
grid on
currenta_sel = currenta(t1>=Tstart&t1<Tstart+T);
currenta_sel(1) = 0;
t1_sel = t1(t1>=Tstart&t1<Tstart+T);
figure(2)%selected time in current measurement (1.6s:4s)
plot(t1_sel,currenta_sel,'r')
title('Selected Time for the Current Measurement');
xlabel('Time [s]');
ylabel('Current [A]');
grid on
%%
ca_hanning = (currenta_sel .*hann(length(currenta_sel)))';
ca_hanning_fft = fftshift(fft(ca_hanning/length(ca_hanning)))';%2
caA_abs = abs(ca_hanning_fft);
caA_abs(1)= 0;
f1= (-fs/2):1/(T-Tstart):(fs/2);
figure(3);
stem(f1,caA_abs, 'r')
set(gca,'yscal','log')
grid on
title('4.6s, Hanning');
xlabel(' \it f (Hz)');
ylabel('|S(j\omega)| [A]');
xlim([0 100])
CaA_abs(1:2:end-1,:)= [];
f1(:,1:2:end-1)= [];
%%
figure(4);
stem(f1,CaA_abs, 'r')
set(gca,'yscal','log')
grid on
title('4kW motor- Hanning window');
xlabel(' \it f (Hz)');
ylabel('|S(j\omega)| (A)');
xlim([0 100])

[KSSV]

To use stem your x and y data should be of same size/ dimensions. In your case they are not. Check why the dimensions are not equal? You need check your variable f1.

[TUAN SHARIFAH NUR FATIEHA]

How to check my f1?

[Rik]

Editing away your question is very rude. Someone spent time reading your question, understanding your issue, figuring out the solution, and writing an answer. Now you repay that kindness by ensuring that the next person with a similar question can't benefit from this answer.

If you used proper citations for anything you didn't write yourself, you should not be adversly affected by a plagiarism scan.

[DGM]

I'm with Rik on this. The only people who should be catching flak for contributions from others are people lazily passing off their routine homework. Asking how to fix a simple usage error or asking for help in debugging is hardly a plagiarism issue when acknowledged transparently.

Personally, I doubt that MATLAB is anything more than a tool in your study. In that sense, is this thread any more detrimental to your ownership of your thesis than any moment you found it necessary to consult a textbook?

[Sam Chak]

OP: I need to delete this question because of this affect my plagiarism [assessment] in thesis.

You probably mean the similarity score. It is unnecessary to delete the question, as you can explore other alternatives.

Alternative #1:

Citing this forum post is likely the best option, as the original concept of the code came from you. However, you have edited the question. Consider restoring it if you choose this alternative. If you have nothing to hide, be transparent.

Alternative #2:

Edit the code in your thesis by renaming some variables. This can be a tedious task.

[Rena Berman]

(Answers Dev) Restored edit

Answer 1

[Walter Roberson]

currenta=out.ScopeData7(:,2);

We are not given any information about what out is or size the various ScopeData* are. We can speculate that they are probably values output by Simulink . It is most common for Simulink scope blocks to be configured to remember only the last 10000 points. It is also common in Simulink for different parts of a model to be run at different intervals, so scope blocks in different parts of a model are not expected to have synchronized times (and so are not expected to have the same number of samples.)

currenta_sel = currenta(t1>=Tstart&t1<Tstart+T);
currenta_sel(1) = 0;
t1_sel = t1(t1>=Tstart&t1<Tstart+T);

You select a subset of the scope data anyhow, and you construct time vectors of similar length.

ca_hanning = (currenta_sel .*hann(length(currenta_sel)))';
ca_hanning_fft = fftshift(fft(ca_hanning/length(ca_hanning)))';%2
caA_abs = abs(ca_hanning_fft);

so caA_abs has size according to what was selected out of the current data.

f1= (-fs/2):1/(T-Tstart):(fs/2);

f1 is going to have size according to some fixed values. The length of f1 is not dependent on what size caA_abs turned out to be -- at least not in any direct way.

Because of cumulative floating point round-off error, you should not expect the colon operator to return the number of entries that it would if you were working algebraically. It is common for a colon operator to end up with one fewer entries than would be expected algebraically.

stem(f1,caA_abs, 'r')

We have no direct reason to expect that the sizes are going to match, and we have round-off-error reason to expect they might e different even if the rest of the calculations were correct.

You should probably be taking something like

f1 = linspace(-fs/2, fs/2, size(caA_abs,1));

[TUAN SHARIFAH NUR FATIEHA]

Thank you!