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