Need command for Continuous time fourier transform
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Ratna
am 17 Sep. 2011
Beantwortet: Juhi Maraskole
am 16 Sep. 2020
Hai, I need command for Continuous time fourier transform.I know the command for Discrete time fourier transform.
One more Question, does the both results of Continuous time fourier transform and Discrete time fourier transform the same, or different.
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Akzeptierte Antwort
Walter Roberson
am 17 Sep. 2011
Continuous and Discrete Fourier Transform are the same in the limit case of the steps being infinitesimals.
Other than that, they cannot be compared as they work on two different kinds of information.
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Weitere Antworten (5)
Wayne King
am 17 Sep. 2011
Hi, If you have the Symbolic Toolbox, you can use fourier() to obtain the Fourier transform.
syms x;
f = exp(-x^2);
fourier(f)
Wayne
3 Kommentare
Wayne King
am 17 Sep. 2011
Hi Ratna, With all due respect, that is not correct.
Please see
>>doc symbolic/fourier
fourier
Fourier integral transform
The examples are not periodic functions of the independent variable.
Wayne
ramakrishna bathini
am 19 Sep. 2011
Hi Wayne,
I am wrong, you are correct. But I have a function to find fourier transform over the limits.
How can I do this? As the above function fourier is for [-infinity to infinity]
Thanks,
Ratna.
Wayne King
am 19 Sep. 2011
Hi Ratna, You can use assume() to place limits on your variable of integration.
For example
syms x
% create Dirac distribution shifted to -1
f = dirac(x+1)
fourier(f)
% gives exp(w*i)
assume(x>0)
fourier(f)
% gives 0
Wayne
1 Kommentar
Abdul Qadeer
am 27 Nov. 2019
hi, how can we find continous time fourier and transform by using for loop. don't use built in func. plz help.
Walter Roberson
am 19 Sep. 2011
I would not recommend the approach of using assumptions. Fourier transforms are defined from -infinity to +infinity and attempts to cheat that are likely to go wrong.
Instead, multiply the function of interest by dirac(x-lowerbound) * dirac(upperbound-x) and fourier() the transformed function.
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Anvesh Samineni
am 31 Okt. 2019
continuous-time Fourier series and transforms:
p(t) = A 0 ≤ t ≤ Tp < T
0 otherwise
how can we write the code for this?
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