Re: Fourier and InverseFourier
- To: mathgroup at smc.vnet.net
- Subject: [mg75636] Re: Fourier and InverseFourier
- From: rob <josh2499 at hotmail.com>
- Date: Mon, 7 May 2007 05:35:17 -0400 (EDT)
- References: <f1c4i8$h4v$1@smc.vnet.net>
Bill Rowe wrote:
> On 5/2/07 at 3:56 AM, josh2499 at hotmail.com (rob) wrote:
>
>
>>Hi, thanks for responding. No, I'm not sure it exists. I tried
>>Exp[-t^2] and it doesn't work either. I haven't yet found a case
>>where InverseFourierTransform[] works so I suspect I'm still doing
>>something wrong.
>
>
> Are you certain you've not previously defined one or more of the
> variables before attempting the InverseTransform? I have no
> difficulty with eitehr Exp[-t] or Exp[-t^2] here. That is:
>
> In[1]:=
> InverseFourierTransform[Exp[-t], t, w]
>
> Out[1]=
> Sqrt[2*Pi]*DiracDelta[w - I]
>
> In[2]:=
> InverseFourierTransform[Exp[-t^2], t, w]
>
> Out[2]=
> 1/(E^(w^2/4)*Sqrt[2])
>
> In[3]:=
> $Version
>
> Out[3]=
> 5.2 for Mac OS X (June 20, 2005)
> --
> To reply via email subtract one hundred and four
>
Here's what doesn't work for me:
fs = FourierTransform[UnitStep[t]*Sin[t], t, w]
fe = FourierTransform[UnitStep[t]*Exp[-t], t, w]
x3[t_] := InverseFourierTransform[fs*fe, w, t]
Plot[x3[t], {t, 0, 15}, PlotRange -> All]
What do you get? Thanks.