Convolution without conv() function
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Hi everybody,
I have a issue to plot a convolution without using the conv() function.
I have x1=sin(2*pi*f1*n*T) and x2=cos(2*pi*f2*n*T)
And i have to plot x3[n] = x1[n] conv x2[n]
I tried many different function like sum, int, symsum but i don't succeed to do it. Is there someone that can help me please
Thank you very much
11 个评论
John D'Errico
2015-4-11
Surely you can write down the convolution on paper as a sum?
So now write it using a loop.
Geoff Hayes
2015-4-11
jackal's answer moved here
Can i use a function a sum fonction that will make it?
Or do i have to make a loop because i need to plot it after.
Thank you
John D'Errico
2015-4-11
No. You cannot write it just with a single call to the function sum. You can write it using a loop and a call to sum, or using a nested pair of for loops.
Just take the formula for a convolution. Then see how it would work using a loop.
Matt J
2015-4-11
jackal's answer moved here
First, thank you a lot for your help.
The teacher gives us as information that for the conv we have to use the formula:
x3[n] = sum for m from -infinity to infinity of x1[n-m]*x2[m]
I don't know how i can represent the infinity sum?
Thank you
Manolis Michailidis
2015-4-11
First i suppose you could say m=1:INF and shift it in a loop every time, the discrete covolution formoula should be ok i think , as for the sum should be computed in the nested loop , so basically you will calculate a new array .
Geoff Hayes
2015-4-11
Jackal's answer moved here
So basically i ll have to calculate for n = 0 to for example 10 and put the result in a array?
Or do i misunderstand?
Geoff Hayes
2015-4-11
@Jackal - if you wish to further the conversation please comment on the above remarks rather than creating answers (which aren't answers to your question).
jackal dr
2015-4-11
Manolis Michailidis
2015-4-11
Yes for example if your signal has lenght n=10 samples you will start for i=1:n+1 (matlab indexing starts from 1) and then yous should calculate in each iteration the sum of your signal with the shifted other , there is a function that does what you are asking take a look http://www.mathworks.com/matlabcentral/fileexchange/23402-convolution-in-matlab-without-using-conv-x-h-
jackal dr
2015-4-11
Image Analyst
2015-4-11
If he won't let you use conv(), then why would he let you use sum()? Seems inconsistent. http://www.mathworks.com/matlabcentral/answers/38787-what-can-be-programmed-without-any-built-in-functions
回答（1 个）
Sk Group
2021-10-25
0 个投票
Convolution without conv function in MATLAB | Complete CODE | Explanation | Example And Output
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