# Convolution under Mathematica 6

• Jun 20th 2009, 11:06 PM
new guy
Convolution under Mathematica 6
Hello everybody ,

I'd like your help with the following problem . Since Mathematica 6 does not has any command that involves Convolution , I defined one myself by the definition of Convolution . I need to have convolution of y(t)=x(t)*h(t)
.
However , when I try to initiate the code , nothing happens . The file is attached , thanks in advance
• Jun 20th 2009, 11:25 PM
CaptainBlack
Quote:

Originally Posted by new guy
Hello everybody ,

I'd like your help with the following problem . Since Mathematica 6 does not has any command that involves Convolution , I defined one myself by the definition of Convolution . I need to have convolution of y(t)=x(t)*h(t)
.
However , when I try to initiate the code , nothing happens . The file is attached , thanks in advance

How does it know what $\Lambda[.]$ denotes (it looks like a function or array to me)?

CB
• Jun 21st 2009, 04:57 AM
new guy
Quote:

Originally Posted by CaptainBlack
How does it know what $\Lambda[.]$ denotes (it looks like a function or array to me)?

CB

You're right of course . I've just added it , as you can see in the file attached to this comment .However even after adding the definition of
$\Lambda[.]$ , nothing happens !
• Jun 21st 2009, 06:10 AM
shawsend
It's better if you cut and past you're code so that we can cut and past it directly into Mathematica. Select it, then do a Cell/Convert To/Raw Input form like I did below. Now you can just cut and paste it directly in your Mathematica and if you want convert it back to standard form.

\[CapitalLambda][t_] :=Piecewise[{{1-Abs[t],Abs[t]<= 1},{0,Abs[t]>= 1}}];
t0 = 9;
s1 = t0 - 6;
x[t_] := Exp[s1*t];
h[t_] := \[CapitalLambda][t/10];
myConvol[t_]=Integrate[x[t - \[Tau]]*h[\[Tau]],
{\[Tau], -Infinity, Infinity}]
• Jun 22nd 2009, 12:23 AM
new guy
Quote:

Originally Posted by shawsend
It's better if you cut and past you're code so that we can cut and past it directly into Mathematica. Select it, then do a Cell/Convert To/Raw Input form like I did below. Now you can just cut and paste it directly in your Mathematica and if you want convert it back to standard form.

\[CapitalLambda][t_] :=Piecewise[{{1-Abs[t],Abs[t]<= 1},{0,Abs[t]>= 1}}];
t0 = 9;
s1 = t0 - 6;
x[t_] := Exp[s1*t];
h[t_] := \[CapitalLambda][t/10];
myConvol[t_]=Integrate[x[t - \[Tau]]*h[\[Tau]],
{\[Tau], -Infinity, Infinity}]

I'll do that . thanks again for the help !