# I should convolve my signal with which function to have the signal itself?

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2NOR_Kh on 11 Jul 2022
Answered: Paul on 11 Jul 2022
I should convolve my signal with a function and have the signal itself. I read on the internet that dirac function will be the solution but I convolved it with my signal and all the points became NaN. I don't know what is the problem. I used the same time line as the time line of my signal.
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2NOR_Kh on 11 Jul 2022
I used this loop:
for i=1:n
%for j=1:1%this is #of frames so for now I am just working on one frame
fgc(:,i)=conv(dirac(tt),e(:,i));
%fg(:,i)=filtfilt(Gt,10,e(:,i));
%end
end
actully I have a RF data of ultrasound that the final result is an image but each line of it is 1D signal, I can apply my conv in both 2D or 1D. In this loop, I applied it in 1D.

2NOR_Kh on 11 Jul 2022
I find out my issue with dirac.
tt = -100:0.1:100
tt = 1×2001
-100.0000 -99.9000 -99.8000 -99.7000 -99.6000 -99.5000 -99.4000 -99.3000 -99.2000 -99.1000 -99.0000 -98.9000 -98.8000 -98.7000 -98.6000 -98.5000 -98.4000 -98.3000 -98.2000 -98.1000 -98.0000 -97.9000 -97.8000 -97.7000 -97.6000 -97.5000 -97.4000 -97.3000 -97.2000 -97.1000
y=dirac(tt);
idx=y==inf;
y(idx)=1;
plot(tt,y); ### More Answers (1)

Paul on 11 Jul 2022
Hi Donya,
dirac is only defined in the Symbolic Math Toolbox and so should only be used for symbolic math, and only for continuous time analysis as well.
The SMT has another function kroneckerDelta that can be cast to a double and used for discrete-domain processing as with conv().
But you can easily write your own unit pulse function for integer-valued input
u = @(n) double(n==0);
This function will, of course, work for non-integer input if that's needed for some reason.

R2021a

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