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remove zeros from sinc function

Hi there,
I am trying to observe the behaviour of the fourier trasform of the sinc function if some of its zeros will be removed. Normally, the sinc function will lead us to rectanglular function in fourier domain, but when I am trying to remove the zeros at 'pi' it is not showing anything due to NaN or infinite. May I request you to pls tell me how to deal with such problem?
Fs=42;Ts=1/Fs;
t=-1:Ts:40*Ts-Ts;
f=5;
y=sinc(t*f)/(1-5*t/(0.9)*pi);
figure;
plot(t,y);
xlabel('x');
ylabel(' magnitude');
fy=fft(y);%figure;
% plot(fy)
fy = fftshift(fy);figure;
plot([abs(fy)])%;angle(fy);real(fy);imag(fy)]','*')

  2 Comments

Jan
on 17 May 2019
It is easier to read, if you include the code directly. Therefore I've copied it from the attachment.
"it is not showing anything due to NaN or infinite" - what is "it" here?
"the plot"- is not showing any thing... no plot.... just blank screen

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1 Answer

Answer by Sulaymon Eshkabilov on 18 May 2019
 Accepted Answer

clearvars; close all
Fs=42;Ts=1/Fs;
t=-1:Ts:1;
f=5;
y=sinc(t*f)./(1-5*t/(0.9)*pi);
figure;
plot(t,y), xlabel('t'), ylabel(' y(t)'); title('Time domain analysis ')
L = length(t); Nblock = 256;
Y = fft(y, Nblock)/L;
f = Fs/2*linspace(0,2, Nblock/2+1);
figure;
plot(f, 2*abs(Y(1:Nblock/2+1))), title('Discrete FFT')
fY = fftshift(Y);figure;
plot(f, 2*abs(fY(1:Nblock/2+1))), title('Shift zero frequency')
figure, plot([angle(fY);real(fY);imag(fY)]','*')
title('Phase angle, Real & Imag components of Shift zero frequency')

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