Re: FourierTransform help
- To: mathgroup at smc.vnet.net
- Subject: [mg72884] Re: FourierTransform help
- From: Jean-Marc Gulliet <jeanmarc.gulliet at gmail.com>
- Date: Wed, 24 Jan 2007 05:34:04 -0500 (EST)
- Organization: The Open University, Milton Keynes, UK
- References: <ep4k9c$qfu$1@smc.vnet.net>
rob wrote:
> I can't seem to plot the result of what I would think would
> be a simple transform. The following code at least attempts
> to run with no errors but it doesn't seem to stop. I plan to
> let it run all night. But surely one of you wizards knows a
> way to get this to output a result quickly. If so, I would
> appreciate your help.
>
>
> s[t_] := Cos[t] Exp[-t^2]
>
> Plot[Abs[Evaluate[FourierTransform[s[t], t, Ï?]]], {Ï?, -3,3}]
>
You should evaluate (and possibly simplify) the Fourier transform first,
then plot the result. For instance,
In[1]:=
s[t_] := Cos[t]*Exp[-t^2]
FourierTransform[s[t], t, Ï?]
FullSimplify[%, Ï? â?? Reals]
ft2[Ï?_] := (E^(-(1/4) - Ï?^2/4)*Cosh[Ï?/2])/Sqrt[2]
Plot[Abs[ft2[Ï?]], {Ï?, -3, 3}];
Regards,
Jean-Marc