# What's the Best Way to Symbolically Define the Periodic Extension of a Finite Duration Signal?

조회 수: 14(최근 30일)
Paul 2021년 9월 27일 21:27
답변: Paul 2021년 10월 23일 14:44
Suppose I have a finite duration signal:
syms s(t)
s(t) = triangularPulse(0,1,1.5,t);
fplot(s(t)) Now I want to define the periodic extension of this signal from t = -inf to inf. I can extend it over a finite duration. For example, with a period P
syms n P real
assumeAlso(n,'integer');
assumeAlso(P,'positive');
sp(t,P) = symsum(s(t - n*P),n,-5,5)
sp(t, P) = fplot(sp(t,3),[-20 20]) And I can evaluate it as well:
sp(1,3)
ans =
1
But extending to infinity doesn't seem to work so well
sp(t,P) = symsum(s(t - n*P),n,-inf,inf)
sp(t, P) = % fplot(sp(t,3),[-20 20]) % code took too long to run
sp(1,3)
ans = Is there a way to define a periodic extension that can be evaluated, integrated, etc.? I feel like there should be a way to do it using rem or mod or something similar ....

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### 답변(1개)

Paul 2021년 10월 23일 14:44
The Symbolic Math Toolbox function mod() changed behavior in 2020b so that (it appears) that such a function can now be easily defined. Link to doc page. I think I was experimenting with mod() in 2019a and that's why it wasn't working for me.
syms s(t)
s(t) = triangularPulse(0,1,1.5,t);
fplot(s(t)) syms P
s_p(t,P) = s(mod(t,P))
s_p(t, P) = fplot(s_p(t,2)) 댓글을 달려면 로그인하십시오.

R2021b

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