# Fourier series and transform of Sinc Function

37 views (last 30 days)
cikalekli on 24 Dec 2021
Commented: Paul on 2 Jan 2022
Does the line spectrum acquired in 2nd have a sinc envelope like the one obtained in 3rd?
Here is my code below:
x = [-5:0.001:5];
y = sinc(x);
plot(x,y);
% 2nd sinc graph:
duty = 0.2;
n = [0:1:15];
cn = 5 * duty * abs(sinc(n*duty));
bar(n*duty,cn);
hold on
% 3rd sinc graph:
n = [0:0.001:3];
plot(x,abs(sinc(x)));

Paul on 1 Jan 2022
Edited: Paul on 1 Jan 2022
Hello @cikalekli,
The second and third graph are both plots of the magnitude of the sinc() function, so it would appear that the third must evelop the first.
Perhaps I've misunderstood the question ....
Paul on 2 Jan 2022
Perhaps a stem plot would be more appropriate for this type of plot
x = [-5:0.001:5];
duty = 0.2;
n = [0:1:15];
cn = 5 * duty * abs(sinc(n*duty));
stem(n*duty,cn); % changed bar to stem
hold on
% 3rd sinc graph:
% n = [0:0.001:3];
plot(x,abs(sinc(x)));

Kshitij Chhabra on 31 Dec 2021
Hi,
You can try leveraging the Curve Fitting Toolbox offering from MATLAB to get insights on how to plot a curve over the bar chart.
You can check the various examples to get a clearer insight. Once the curve is optained, you can compare the values between the two plots.
Hope it helps!
##### 2 CommentsShowHide 1 older comment
cikalekli on 1 Jan 2022
Edited: cikalekli on 1 Jan 2022
I apologize for my inappropriate behavior. But I asked everything clearly in my question. I never expected an answer from anyone. I just wanted to ask about the correctness and relevance of my code. That's why I reacted to such a response that came days later. Where did I go wrong? I wonder if I should have asked differently when asking a question? What is the error in my question while posting here please? Again pardon me and I am not going to do the same mistake ever again. Thank you for your understanding as well.
Edit: Typo correction.

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