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Re: Convolution Integral

• To: mathgroup at smc.vnet.net
• Subject: [mg72735] Re: Convolution Integral
• From: "dimitris" <dimmechan at yahoo.com>
• Date: Wed, 17 Jan 2007 06:28:39 -0500 (EST)
• References: <eoht0r$pti$1@smc.vnet.net>

Hello.

Here is one place to look.

http://mathworld.wolfram.com/Convolution.html

Cheers,
Dimitris

Mr Ajit Sen wrote:
> Dear Mathgroup,
>
> Could anyone please help me with the following?
>
>  I'd like to find the convolution of 2 arbitrary
> functions, f(t) and g(t) in the Laplace transform
> sense,i.e.,
>
> convolve[f[t],g[t]]=Integrate[f[u]*g[t-u],{u,0,t}]
>
> Thus, I'd like convolve[Sin[t],Exp[-t]] to return
>
>    (Exp[-t]-Cos[t]+Sin[t])/2 .
>
> My several attempts with function definitions such as
>
>   convolve[f_,g_]:=Integrate[f[u]*g[t-u],{u,0,t}]
>
>
> convolve[f[t_],g[t_]]:=Integrate[f[u]*g[t-u],{u,0,t}]
>
>   convolve[f_,g_][t_]:=Integrate[f[u]*g[t-u],{u,0,t}]
>
> all failed (because of the dummy u ? )
>
> Thanks in advance.
> Sen.
>
>
>
>
>
>
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